matplotlib-devel Mailing List for matplotlib (Page 2)

Sorry, I may have been being a bit dramatic

In mpl.patches: Arrow, FancyArrow, YAArrow, FancyArrowPatch,
ConnectionPatch  + annotation related artists + some classes in axisartist
which now that I look at them are not really general purpose arrow tools.
I had not been counting quiver (or barbs) or sankey.

Neil: Those are all great questions!  Much of the arrow related code was
written by Joe-Joon Lee who (by having read a good deal of his code) has a
habit of writing very power but very opaque python.

I believe that the line join style is controlled by `joinstyle` on the
graphics context and it is up to the backends to implement that correctly.

Tom

On Wed, May 13, 2015 at 10:58 PM Neil Girdhar <mis...@gm...> wrote:

> Okay, I'm looking at this in more detail and there may be some design
> concerns:
>
> The arrow placement is decided without asking the arrow any questions,
> such as its bounding box.  Instead, the arrow should return a bounding box
> and then the line should retreat until the bounding box no longer
> intersects the target node.  Then the arrow should be placed.  This doesn't
> matter so much when you have a simple arrow like this: ---->, but it's a
> big deal when you have an arrow like ----| .  In this case, the sides of
> the arrow risk intersecting with the target node.
>
> I'm not keen on implementing every arrow three times: <-, ->, <->.  This
> really should be handled by the code placing the arrows for many reasons:
> 1. It should also be possible to have a different arrowhead at either end
> of the line.
> 2. It should be possible to stack the arrows, for example having two heads
> one after another (to represent two kinds of relationships).  This is
> another reason to be able to ask the arrowhead its length and so on.
>
> I don't understand the "monolithic" keyword.  How can the arrow draw the
> line as well when it doesn't know the line style, color and so on?
>
> I think I like the design of the transmute function.  I'm curious:
> ultimately, where does the mutation_size come from?  Is it a global scale
> applied to the figure, or is it based on the linewidth, or?
>
> When you emit a set of lines, how are they joined?  If I draw a line
> having linewidth 0.1 from the origin to (1, 0), and back to (0, 0.5), what
> happens at the tip?  Are two rectangles drawn (each having width 0.1, but
> oriented differently)?  Is a bevel created?  A miter? Or is the tip
> rounded?  Can this be controlled?  See page 166 of the manual I sent
> earlier (search for tikz/line join).
>
> Best,
>
> Neil
>
> On Wed, May 13, 2015 at 10:14 PM, Neil Girdhar <mis...@gm...>
> wrote:
>
>> Thanks, it works!
>>
>> I needed to add:
>>
>> import matplotlib.patches
>>
>> to one file and
>>
>> plt.show()
>>
>> to the other.
>>
>> Any word on the locations in the code of the seven arrow drawing methods?
>>
>> I've located the arrow drawing code in tikz, and so I can start porting
>> it over.  I'm curious, do we know the linewidth of the edge being decorated
>> by the arrow?  To make arrows scale nicely, most of the arrow dimensions
>> are given in two pieces: an absolute value (in points for example) and a
>> line width factor.  The dimension is the absolute value plus the line width
>> factor times the line width.  The TikZ manual explains: "This makes it easy
>> to vary the size of an arrow tip in accordance with the line width –
>> usually a very good idea since thicker lines will need thicker arrow tips."
>>
>> Best,
>>
>> Neil
>>
>> On Wed, May 13, 2015 at 10:07 PM, Benjamin Reedlunn <bre...@gm...>
>> wrote:
>>
>>> Neil,
>>>
>>> I have attached code to draw the arrowhead.
>>>
>>> -Ben
>>>
>>>
>>>
>>> On May 13, 2015, at 7:44 PM, Neil Girdhar <mis...@gm...> wrote:
>>>
>>> Do you have the code that you used to draw the arrowhead?  I'm up to
>>> date now on the development workflow (
>>> http://matplotlib.org/devel/gitwash/development_workflow.html), so I'm
>>> ready to start working.
>>>
>>> Thanks,
>>>
>>> Neil
>>>
>>> On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn <bre...@gm...>
>>> wrote:
>>>
>>>> Yes, I fully agree that we need to unify the many different ways to
>>>> draw arrows.
>>>>
>>>> Neil, in case an example would be helpful for you, I have attached a
>>>> module that includes a custom arrowhead class.  The arrowhead class works
>>>> with the with the ax.annotate() method.  (I like the annotate method
>>>> because it allows me to easily mix and match coordinate systems for arrow
>>>> placement.)  As you can see in the attached pdf, the custom arrowhead
>>>> doesn't include fancy Bezier curves, but that could be added.
>>>>
>>>> -Ben
>>>>
>>>>
>>>>
>>>> On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:
>>>>
>>>> The other thing that should be done is to unify the (I think 7?!?)
>>>> unique ways to draw arrows in mpl.
>>>>
>>>> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...>
>>>> wrote:
>>>>
>>>>> Yes, I just noticed that as well.  That's how the tikz pgf code looks
>>>>> (a sequence of line_to and curve_to commands and so on) so it should be
>>>>> easy to port over the various shapes.
>>>>>
>>>>> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...>
>>>>> wrote:
>>>>>
>>>>>> On 2015/05/13 10:12 AM, Neil Girdhar wrote:
>>>>>>
>>>>>>> If you want to make arrowheads look at all decent, they really need
>>>>>>> to
>>>>>>> be enclosed in Bezier curves.  See the diagram here:
>>>>>>>
>>>>>>
>>>>>> Mpl paths support Bezier curves.
>>>>>> http://matplotlib.org/api/path_api.html?highlight=bezier
>>>>>>
>>>>>>
>>>>>>>
>>>>>>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>>>>>>
>>>>>>> The first two look like garbage.  The last one is the only one that
>>>>>>> looks good imho.
>>>>>>>
>>>>>>
>>>>>> That depends on the application, and the observer.
>>>>>
>>>>>
>>>>> Sure, but I may as well port them all of the tikz arrowheads over
>>>>> since most of the work would be figuring out how to do it.
>>>>>
>>>>>
>>>>>>
>>>>>>
>>>>>> Eric
>>>>>>
>>>>>>
>>>>>>> Best,
>>>>>>>
>>>>>>> Neil
>>>>>>>
>>>>>>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>>>>>>> <mailto:ef...@ha...>> wrote:
>>>>>>>
>>>>>>>     On 2015/05/13 9:36 AM, Neil Girdhar wrote:
>>>>>>>
>>>>>>>         I don't know matplotlib well enough (yet) to know what the
>>>>>>>         change would
>>>>>>>         consist of.
>>>>>>>
>>>>>>>         I suggest you take a look at the beautiful tikz manual:
>>>>>>>         http://pgf.sourceforge.net/pgf_CVS.pdf
>>>>>>>
>>>>>>>
>>>>>>>     Very helpful, thank you.
>>>>>>>
>>>>>>>
>>>>>>>         The arrows.meta on page 201–212 are really well-designed and
>>>>>>>         beautiful.
>>>>>>>
>>>>>>>         Compare this with matplotlib's custom arrows:
>>>>>>>
>>>>>>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>>>>>>
>>>>>>>         How do I make tikz's arrowheads available for all backends?
>>>>>>>
>>>>>>>
>>>>>>>     My guess offhand is that this is a matter of using the mpl API.
>>>>>>> I
>>>>>>>     don't think we would want to add all of these types and options
>>>>>>> to
>>>>>>>     the mpl core; but a toolkit might be ideal for this.  The mpl
>>>>>>> API,
>>>>>>>     which generates the same results for all backends, is quite
>>>>>>> complete
>>>>>>>     and flexible.  Things like arrowheads are Patch objects, and you
>>>>>>> can
>>>>>>>     specify any path you want.  The main trick is figuring out how to
>>>>>>>     handle transforms--what kind of coordinates should the path be
>>>>>>>     specifying?  How should things scale as a figure is reshaped and
>>>>>>>     resized?
>>>>>>>
>>>>>>>     For many of these types you could also use mpl Line2D objects,
>>>>>>> for
>>>>>>>     which several properties including cap style can be specified.
>>>>>>> Not
>>>>>>>     all of the TikZ options would be available, but perhaps enough.
>>>>>>>
>>>>>>>     Eric
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>> ------------------------------------------------------------------------------
>>>>> One dashboard for servers and applications across
>>>>> Physical-Virtual-Cloud
>>>>> Widest out-of-the-box monitoring support with 50+ applications
>>>>> Performance metrics, stats and reports that give you Actionable
>>>>> Insights
>>>>> Deep dive visibility with transaction tracing using APM Insight.
>>>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>>>>> _______________________________________________
>>>>> Matplotlib-devel mailing list
>>>>> Mat...@li...
>>>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>>>
>>>>
>>>> ------------------------------------------------------------------------------
>>>> One dashboard for servers and applications across
>>>> Physical-Virtual-Cloud
>>>> Widest out-of-the-box monitoring support with 50+ applications
>>>> Performance metrics, stats and reports that give you Actionable Insights
>>>> Deep dive visibility with transaction tracing using APM Insight.
>>>>
>>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>>>> Matplotlib-devel mailing list
>>>> Mat...@li...
>>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
>

I don't want to ruffle any feathers, and I'm sure this comes up all the
time, but I'm wondering why don't we have a decorator on classes that
generates all of the boilerplate methods?

For example:

@generate_boilerplate([('linestyle', 'ls'), …]
class Patch(…):

would generate

get_ls, set_ls to point to get_linestyle and set_linestyle and their
docstrings

and would generate

linestyle = property(get_linestyle, set_linestyle) and their docstring.

This would reduce a lot of boilerplate code and provide the modern getters
and setters.  In the future, a user could enable an option to disable the
old style interface and remove it from 'dir', etc.

What's the reason for not providing the "new"-style getters and setters?

Okay, I'm looking at this in more detail and there may be some design
concerns:

The arrow placement is decided without asking the arrow any questions, such
as its bounding box.  Instead, the arrow should return a bounding box and
then the line should retreat until the bounding box no longer intersects
the target node.  Then the arrow should be placed.  This doesn't matter so
much when you have a simple arrow like this: ---->, but it's a big deal
when you have an arrow like ----| .  In this case, the sides of the arrow
risk intersecting with the target node.

I'm not keen on implementing every arrow three times: <-, ->, <->.  This
really should be handled by the code placing the arrows for many reasons:
1. It should also be possible to have a different arrowhead at either end
of the line.
2. It should be possible to stack the arrows, for example having two heads
one after another (to represent two kinds of relationships).  This is
another reason to be able to ask the arrowhead its length and so on.

I don't understand the "monolithic" keyword.  How can the arrow draw the
line as well when it doesn't know the line style, color and so on?

I think I like the design of the transmute function.  I'm curious:
ultimately, where does the mutation_size come from?  Is it a global scale
applied to the figure, or is it based on the linewidth, or?

When you emit a set of lines, how are they joined?  If I draw a line having
linewidth 0.1 from the origin to (1, 0), and back to (0, 0.5), what happens
at the tip?  Are two rectangles drawn (each having width 0.1, but oriented
differently)?  Is a bevel created?  A miter? Or is the tip rounded?  Can
this be controlled?  See page 166 of the manual I sent earlier (search for
tikz/line join).

Best,

Neil

On Wed, May 13, 2015 at 10:14 PM, Neil Girdhar <mis...@gm...>
wrote:

> Thanks, it works!
>
> I needed to add:
>
> import matplotlib.patches
>
> to one file and
>
> plt.show()
>
> to the other.
>
> Any word on the locations in the code of the seven arrow drawing methods?
>
> I've located the arrow drawing code in tikz, and so I can start porting it
> over.  I'm curious, do we know the linewidth of the edge being decorated by
> the arrow?  To make arrows scale nicely, most of the arrow dimensions are
> given in two pieces: an absolute value (in points for example) and a line
> width factor.  The dimension is the absolute value plus the line width
> factor times the line width.  The TikZ manual explains: "This makes it easy
> to vary the size of an arrow tip in accordance with the line width –
> usually a very good idea since thicker lines will need thicker arrow tips."
>
> Best,
>
> Neil
>
> On Wed, May 13, 2015 at 10:07 PM, Benjamin Reedlunn <bre...@gm...>
> wrote:
>
>> Neil,
>>
>> I have attached code to draw the arrowhead.
>>
>> -Ben
>>
>>
>>
>> On May 13, 2015, at 7:44 PM, Neil Girdhar <mis...@gm...> wrote:
>>
>> Do you have the code that you used to draw the arrowhead?  I'm up to date
>> now on the development workflow (
>> http://matplotlib.org/devel/gitwash/development_workflow.html), so I'm
>> ready to start working.
>>
>> Thanks,
>>
>> Neil
>>
>> On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn <bre...@gm...>
>> wrote:
>>
>>> Yes, I fully agree that we need to unify the many different ways to draw
>>> arrows.
>>>
>>> Neil, in case an example would be helpful for you, I have attached a
>>> module that includes a custom arrowhead class.  The arrowhead class works
>>> with the with the ax.annotate() method.  (I like the annotate method
>>> because it allows me to easily mix and match coordinate systems for arrow
>>> placement.)  As you can see in the attached pdf, the custom arrowhead
>>> doesn't include fancy Bezier curves, but that could be added.
>>>
>>> -Ben
>>>
>>>
>>>
>>> On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:
>>>
>>> The other thing that should be done is to unify the (I think 7?!?)
>>> unique ways to draw arrows in mpl.
>>>
>>> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...>
>>> wrote:
>>>
>>>> Yes, I just noticed that as well.  That's how the tikz pgf code looks
>>>> (a sequence of line_to and curve_to commands and so on) so it should be
>>>> easy to port over the various shapes.
>>>>
>>>> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...>
>>>> wrote:
>>>>
>>>>> On 2015/05/13 10:12 AM, Neil Girdhar wrote:
>>>>>
>>>>>> If you want to make arrowheads look at all decent, they really need to
>>>>>> be enclosed in Bezier curves.  See the diagram here:
>>>>>>
>>>>>
>>>>> Mpl paths support Bezier curves.
>>>>> http://matplotlib.org/api/path_api.html?highlight=bezier
>>>>>
>>>>>
>>>>>>
>>>>>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>>>>>
>>>>>> The first two look like garbage.  The last one is the only one that
>>>>>> looks good imho.
>>>>>>
>>>>>
>>>>> That depends on the application, and the observer.
>>>>
>>>>
>>>> Sure, but I may as well port them all of the tikz arrowheads over since
>>>> most of the work would be figuring out how to do it.
>>>>
>>>>
>>>>>
>>>>>
>>>>> Eric
>>>>>
>>>>>
>>>>>> Best,
>>>>>>
>>>>>> Neil
>>>>>>
>>>>>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>>>>>> <mailto:ef...@ha...>> wrote:
>>>>>>
>>>>>>     On 2015/05/13 9:36 AM, Neil Girdhar wrote:
>>>>>>
>>>>>>         I don't know matplotlib well enough (yet) to know what the
>>>>>>         change would
>>>>>>         consist of.
>>>>>>
>>>>>>         I suggest you take a look at the beautiful tikz manual:
>>>>>>         http://pgf.sourceforge.net/pgf_CVS.pdf
>>>>>>
>>>>>>
>>>>>>     Very helpful, thank you.
>>>>>>
>>>>>>
>>>>>>         The arrows.meta on page 201–212 are really well-designed and
>>>>>>         beautiful.
>>>>>>
>>>>>>         Compare this with matplotlib's custom arrows:
>>>>>>
>>>>>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>>>>>
>>>>>>         How do I make tikz's arrowheads available for all backends?
>>>>>>
>>>>>>
>>>>>>     My guess offhand is that this is a matter of using the mpl API.  I
>>>>>>     don't think we would want to add all of these types and options to
>>>>>>     the mpl core; but a toolkit might be ideal for this.  The mpl API,
>>>>>>     which generates the same results for all backends, is quite
>>>>>> complete
>>>>>>     and flexible.  Things like arrowheads are Patch objects, and you
>>>>>> can
>>>>>>     specify any path you want.  The main trick is figuring out how to
>>>>>>     handle transforms--what kind of coordinates should the path be
>>>>>>     specifying?  How should things scale as a figure is reshaped and
>>>>>>     resized?
>>>>>>
>>>>>>     For many of these types you could also use mpl Line2D objects, for
>>>>>>     which several properties including cap style can be specified.
>>>>>> Not
>>>>>>     all of the TikZ options would be available, but perhaps enough.
>>>>>>
>>>>>>     Eric
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>> ------------------------------------------------------------------------------
>>>> One dashboard for servers and applications across Physical-Virtual-Cloud
>>>> Widest out-of-the-box monitoring support with 50+ applications
>>>> Performance metrics, stats and reports that give you Actionable Insights
>>>> Deep dive visibility with transaction tracing using APM Insight.
>>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>>>> _______________________________________________
>>>> Matplotlib-devel mailing list
>>>> Mat...@li...
>>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>>
>>>
>>> ------------------------------------------------------------------------------
>>> One dashboard for servers and applications across Physical-Virtual-Cloud
>>> Widest out-of-the-box monitoring support with 50+ applications
>>> Performance metrics, stats and reports that give you Actionable Insights
>>> Deep dive visibility with transaction tracing using APM Insight.
>>>
>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>>> Matplotlib-devel mailing list
>>> Mat...@li...
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>
>>>
>>>
>>>
>>
>>
>>
>

On 2015/05/13 4:14 PM, Neil Girdhar wrote:
> Thanks, it works!
>
> I needed to add:
>
> import matplotlib.patches
>
> to one file and
>
> plt.show()
>
> to the other.
>
> Any word on the locations in the code of the seven arrow drawing methods?

I'm not sure how to get to a count of seven.  One of them is in the 
quiver module, but it is very different from the others, and at least 
for now I suggest you ignore it.  Probably everything else is in the 
patches module, and much of it is called in the text module.  Maybe 
Thomas is counting the text module usage. Ah, yes, and then there is the 
sankey module.

See also https://github.com/matplotlib/matplotlib/pull/4178.

Eric

>
> I've located the arrow drawing code in tikz, and so I can start porting
> it over.  I'm curious, do we know the linewidth of the edge being
> decorated by the arrow?  To make arrows scale nicely, most of the arrow
> dimensions are given in two pieces: an absolute value (in points for
> example) and a line width factor.  The dimension is the absolute value
> plus the line width factor times the line width.  The TikZ manual
> explains: "This makes it easy to vary the size of an arrow tip in
> accordance with the line width – usually a very good idea since thicker
> lines will need thicker arrow tips."
>
> Best,
>
> Neil
>
> On Wed, May 13, 2015 at 10:07 PM, Benjamin Reedlunn <bre...@gm...
> <mailto:bre...@gm...>> wrote:
>
>     Neil,
>
>     I have attached code to draw the arrowhead.
>
>     -Ben
>
>
>
>     On May 13, 2015, at 7:44 PM, Neil Girdhar <mis...@gm...
>     <mailto:mis...@gm...>> wrote:
>
>>     Do you have the code that you used to draw the arrowhead?  I'm up
>>     to date now on the development workflow
>>     (http://matplotlib.org/devel/gitwash/development_workflow.html),
>>     so I'm ready to start working.
>>
>>     Thanks,
>>
>>     Neil
>>
>>     On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn
>>     <bre...@gm... <mailto:bre...@gm...>> wrote:
>>
>>         Yes, I fully agree that we need to unify the many different
>>         ways to draw arrows.
>>
>>         Neil, in case an example would be helpful for you, I have
>>         attached a module that includes a custom arrowhead class.  The
>>         arrowhead class works with the with the ax.annotate() method.
>>          (I like the annotate method because it allows me to easily
>>         mix and match coordinate systems for arrow placement.)  As you
>>         can see in the attached pdf, the custom arrowhead doesn't
>>         include fancy Bezier curves, but that could be added.
>>
>>         -Ben
>>
>>
>>
>>         On May 13, 2015, at 2:54 PM, Thomas Caswell
>>         <tca...@gm... <mailto:tca...@gm...>> wrote:
>>
>>>         The other thing that should be done is to unify the (I think
>>>         7?!?) unique ways to draw arrows in mpl.
>>>
>>>         On Wed, May 13, 2015 at 4:52 PM Neil Girdhar
>>>         <mis...@gm... <mailto:mis...@gm...>> wrote:
>>>
>>>             Yes, I just noticed that as well.  That's how the tikz
>>>             pgf code looks (a sequence of line_to and curve_to
>>>             commands and so on) so it should be easy to port over the
>>>             various shapes.
>>>
>>>             On Wed, May 13, 2015 at 4:49 PM, Eric Firing
>>>             <ef...@ha... <mailto:ef...@ha...>> wrote:
>>>
>>>                 On 2015/05/13 10:12 AM, Neil Girdhar wrote:
>>>
>>>                     If you want to make arrowheads look at all
>>>                     decent, they really need to
>>>                     be enclosed in Bezier curves.  See the diagram here:
>>>
>>>
>>>                 Mpl paths support Bezier curves.
>>>                 http://matplotlib.org/api/path_api.html?highlight=bezier
>>>
>>>
>>>                     http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>>
>>>                     The first two look like garbage.  The last one is
>>>                     the only one that
>>>                     looks good imho.
>>>
>>>
>>>                 That depends on the application, and the observer.
>>>
>>>
>>>             Sure, but I may as well port them all of the tikz
>>>             arrowheads over since most of the work would be figuring
>>>             out how to do it.
>>>
>>>
>>>
>>>                 Eric
>>>
>>>
>>>                     Best,
>>>
>>>                     Neil
>>>
>>>                     On Wed, May 13, 2015 at 4:09 PM, Eric Firing
>>>                     <ef...@ha... <mailto:ef...@ha...>
>>>                     <mailto:ef...@ha...
>>>                     <mailto:ef...@ha...>>> wrote:
>>>
>>>                         On 2015/05/13 9:36 AM, Neil Girdhar wrote:
>>>
>>>                             I don't know matplotlib well enough (yet)
>>>                     to know what the
>>>                             change would
>>>                             consist of.
>>>
>>>                             I suggest you take a look at the
>>>                     beautiful tikz manual:
>>>                     http://pgf.sourceforge.net/pgf_CVS.pdf
>>>
>>>
>>>                         Very helpful, thank you.
>>>
>>>
>>>                             The arrows.meta on page 201–212 are
>>>                     really well-designed and
>>>                             beautiful.
>>>
>>>                             Compare this with matplotlib's custom arrows:
>>>                     http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>>
>>>                             How do I make tikz's arrowheads available
>>>                     for all backends?
>>>
>>>
>>>                         My guess offhand is that this is a matter of
>>>                     using the mpl API.  I
>>>                         don't think we would want to add all of these
>>>                     types and options to
>>>                         the mpl core; but a toolkit might be ideal
>>>                     for this.  The mpl API,
>>>                         which generates the same results for all
>>>                     backends, is quite complete
>>>                         and flexible.  Things like arrowheads are
>>>                     Patch objects, and you can
>>>                         specify any path you want.  The main trick is
>>>                     figuring out how to
>>>                         handle transforms--what kind of coordinates
>>>                     should the path be
>>>                         specifying?  How should things scale as a
>>>                     figure is reshaped and
>>>                         resized?
>>>
>>>                         For many of these types you could also use
>>>                     mpl Line2D objects, for
>>>                         which several properties including cap style
>>>                     can be specified.  Not
>>>                         all of the TikZ options would be available,
>>>                     but perhaps enough.
>>>
>>>                         Eric
>>>
>>>
>>>
>>>             ------------------------------------------------------------------------------
>>>             One dashboard for servers and applications across
>>>             Physical-Virtual-Cloud
>>>             Widest out-of-the-box monitoring support with 50+
>>>             applications
>>>             Performance metrics, stats and reports that give you
>>>             Actionable Insights
>>>             Deep dive visibility with transaction tracing using APM
>>>             Insight.
>>>             http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>>>             Matplotlib-devel mailing list
>>>             Mat...@li...
>>>             <mailto:Mat...@li...>
>>>             https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>
>>>         ------------------------------------------------------------------------------
>>>         One dashboard for servers and applications across
>>>         Physical-Virtual-Cloud
>>>         Widest out-of-the-box monitoring support with 50+ applications
>>>         Performance metrics, stats and reports that give you
>>>         Actionable Insights
>>>         Deep dive visibility with transaction tracing using APM Insight.
>>>         http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>>>         Matplotlib-devel mailing list
>>>         Mat...@li...
>>>         <mailto:Mat...@li...>
>>>         https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>>
>>
>
>
>

Thanks Tom! Absolutely fascinating! I was trying to grok this and thinking,
"but what if we want 'or' to return a value that will later be used as a
conditional, surely it should return bool?" But of course whatever it
returns will be correctly interpreted as a bool in a conditional context!
Delayed/lazy bool casting, in a sense. Very clever indeed.

There's quite a few places where this would make my code quite a bit
cleaner! =)

Thanks again!

Juan.

On Thu, May 14, 2015 at 12:21 PM, Thomas Caswell <tca...@gm...> wrote:

> The `a or b` syntax evaluates if a is 'trueish' and if so returns a if not
> returns b so `c = None or {}` -> c == {}  but `c = {'a': 1} or {}` -> c ==
> {'a': 1}
>
> See
> https://docs.python.org/3.5/reference/expressions.html#grammar-token-or_test
> for the docs on or. and works almost the same, but returns a if a is False
> and b in a is True.
>
> In the grammar for calls it should be looking for thing like "'**'
> expression" which means in the parsing anything that is part of the
> expression gets evaluated before the unpacking of the mapping.  If you
> chase far enough back in the grammar an 'or_test' is an 'expression' (I may
> be butchering the terminology here, only just learned how lexing/parsing
> works a few weeks ago) so it should be fully evaluated before trying to
> unpack.
>
> See https://docs.python.org/3.5/reference/expressions.html#calls for the
> official docs.
>
> I suspect the source of this bug is that the grammar is getting rearranged
> a bit to allow for things like d = {**other_dict, 'x':6}  and b = (*a, *c)
> to work as expected and something did not get changed quite right.
>
> Tom
>
> On Wed, May 13, 2015 at 8:33 PM Juan Nunez-Iglesias <jni...@gm...>
> wrote:
>
>> Fascinating! Can you "unpack" (heh) that error for us mere mortals? In
>> particular:
>>
>> - never seen that "or" syntax before... Is it coercing both expressions
>> as bool, or is it evaluating to left if bool(left) evaluates to True, else
>> to right?
>> - Why do you expect the second expression to work? Is ** supposed to have
>> lower preference than "or"? (Which seems weird to me.)
>>
>> Thanks!
>>
>> Juan.
>>
>> On Thu, May 14, 2015 at 5:08 AM, Thomas Caswell <tca...@gm...>
>> wrote:
>>
>>>
>>> The failures on python nightly are currently due to a bug in python (
>>> http://bugs.python.org/issue24176)
>>>
>>> Tom
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> One dashboard for servers and applications across Physical-Virtual-Cloud
>>> Widest out-of-the-box monitoring support with 50+ applications
>>> Performance metrics, stats and reports that give you Actionable Insights
>>> Deep dive visibility with transaction tracing using APM Insight.
>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>>> _______________________________________________
>>> Matplotlib-devel mailing list
>>> Mat...@li...
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>
>>>
>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>

The `a or b` syntax evaluates if a is 'trueish' and if so returns a if not
returns b so `c = None or {}` -> c == {}  but `c = {'a': 1} or {}` -> c ==
{'a': 1}

See
https://docs.python.org/3.5/reference/expressions.html#grammar-token-or_test
for the docs on or. and works almost the same, but returns a if a is False
and b in a is True.

In the grammar for calls it should be looking for thing like "'**'
expression" which means in the parsing anything that is part of the
expression gets evaluated before the unpacking of the mapping.  If you
chase far enough back in the grammar an 'or_test' is an 'expression' (I may
be butchering the terminology here, only just learned how lexing/parsing
works a few weeks ago) so it should be fully evaluated before trying to
unpack.

See https://docs.python.org/3.5/reference/expressions.html#calls for the
official docs.

I suspect the source of this bug is that the grammar is getting rearranged
a bit to allow for things like d = {**other_dict, 'x':6}  and b = (*a, *c)
to work as expected and something did not get changed quite right.

Tom

On Wed, May 13, 2015 at 8:33 PM Juan Nunez-Iglesias <jni...@gm...>
wrote:

> Fascinating! Can you "unpack" (heh) that error for us mere mortals? In
> particular:
>
> - never seen that "or" syntax before... Is it coercing both expressions as
> bool, or is it evaluating to left if bool(left) evaluates to True, else to
> right?
> - Why do you expect the second expression to work? Is ** supposed to have
> lower preference than "or"? (Which seems weird to me.)
>
> Thanks!
>
> Juan.
>
> On Thu, May 14, 2015 at 5:08 AM, Thomas Caswell <tca...@gm...>
> wrote:
>
>>
>> The failures on python nightly are currently due to a bug in python (
>> http://bugs.python.org/issue24176)
>>
>> Tom
>>
>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>

Thanks, it works!

I needed to add:

import matplotlib.patches

to one file and

plt.show()

to the other.

Any word on the locations in the code of the seven arrow drawing methods?

I've located the arrow drawing code in tikz, and so I can start porting it
over.  I'm curious, do we know the linewidth of the edge being decorated by
the arrow?  To make arrows scale nicely, most of the arrow dimensions are
given in two pieces: an absolute value (in points for example) and a line
width factor.  The dimension is the absolute value plus the line width
factor times the line width.  The TikZ manual explains: "This makes it easy
to vary the size of an arrow tip in accordance with the line width –
usually a very good idea since thicker lines will need thicker arrow tips."

Best,

Neil

On Wed, May 13, 2015 at 10:07 PM, Benjamin Reedlunn <bre...@gm...>
wrote:

> Neil,
>
> I have attached code to draw the arrowhead.
>
> -Ben
>
>
>
> On May 13, 2015, at 7:44 PM, Neil Girdhar <mis...@gm...> wrote:
>
> Do you have the code that you used to draw the arrowhead?  I'm up to date
> now on the development workflow (
> http://matplotlib.org/devel/gitwash/development_workflow.html), so I'm
> ready to start working.
>
> Thanks,
>
> Neil
>
> On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn <bre...@gm...>
> wrote:
>
>> Yes, I fully agree that we need to unify the many different ways to draw
>> arrows.
>>
>> Neil, in case an example would be helpful for you, I have attached a
>> module that includes a custom arrowhead class.  The arrowhead class works
>> with the with the ax.annotate() method.  (I like the annotate method
>> because it allows me to easily mix and match coordinate systems for arrow
>> placement.)  As you can see in the attached pdf, the custom arrowhead
>> doesn't include fancy Bezier curves, but that could be added.
>>
>> -Ben
>>
>>
>>
>> On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:
>>
>> The other thing that should be done is to unify the (I think 7?!?) unique
>> ways to draw arrows in mpl.
>>
>> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...>
>> wrote:
>>
>>> Yes, I just noticed that as well.  That's how the tikz pgf code looks (a
>>> sequence of line_to and curve_to commands and so on) so it should be easy
>>> to port over the various shapes.
>>>
>>> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...> wrote:
>>>
>>>> On 2015/05/13 10:12 AM, Neil Girdhar wrote:
>>>>
>>>>> If you want to make arrowheads look at all decent, they really need to
>>>>> be enclosed in Bezier curves.  See the diagram here:
>>>>>
>>>>
>>>> Mpl paths support Bezier curves.
>>>> http://matplotlib.org/api/path_api.html?highlight=bezier
>>>>
>>>>
>>>>>
>>>>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>>>>
>>>>> The first two look like garbage.  The last one is the only one that
>>>>> looks good imho.
>>>>>
>>>>
>>>> That depends on the application, and the observer.
>>>
>>>
>>> Sure, but I may as well port them all of the tikz arrowheads over since
>>> most of the work would be figuring out how to do it.
>>>
>>>
>>>>
>>>>
>>>> Eric
>>>>
>>>>
>>>>> Best,
>>>>>
>>>>> Neil
>>>>>
>>>>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>>>>> <mailto:ef...@ha...>> wrote:
>>>>>
>>>>>     On 2015/05/13 9:36 AM, Neil Girdhar wrote:
>>>>>
>>>>>         I don't know matplotlib well enough (yet) to know what the
>>>>>         change would
>>>>>         consist of.
>>>>>
>>>>>         I suggest you take a look at the beautiful tikz manual:
>>>>>         http://pgf.sourceforge.net/pgf_CVS.pdf
>>>>>
>>>>>
>>>>>     Very helpful, thank you.
>>>>>
>>>>>
>>>>>         The arrows.meta on page 201–212 are really well-designed and
>>>>>         beautiful.
>>>>>
>>>>>         Compare this with matplotlib's custom arrows:
>>>>>
>>>>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>>>>
>>>>>         How do I make tikz's arrowheads available for all backends?
>>>>>
>>>>>
>>>>>     My guess offhand is that this is a matter of using the mpl API.  I
>>>>>     don't think we would want to add all of these types and options to
>>>>>     the mpl core; but a toolkit might be ideal for this.  The mpl API,
>>>>>     which generates the same results for all backends, is quite
>>>>> complete
>>>>>     and flexible.  Things like arrowheads are Patch objects, and you
>>>>> can
>>>>>     specify any path you want.  The main trick is figuring out how to
>>>>>     handle transforms--what kind of coordinates should the path be
>>>>>     specifying?  How should things scale as a figure is reshaped and
>>>>>     resized?
>>>>>
>>>>>     For many of these types you could also use mpl Line2D objects, for
>>>>>     which several properties including cap style can be specified.  Not
>>>>>     all of the TikZ options would be available, but perhaps enough.
>>>>>
>>>>>     Eric
>>>>>
>>>>>
>>>>>
>>>>
>>> ------------------------------------------------------------------------------
>>> One dashboard for servers and applications across Physical-Virtual-Cloud
>>> Widest out-of-the-box monitoring support with 50+ applications
>>> Performance metrics, stats and reports that give you Actionable Insights
>>> Deep dive visibility with transaction tracing using APM Insight.
>>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>>> _______________________________________________
>>> Matplotlib-devel mailing list
>>> Mat...@li...
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>>
>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>>
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>>
>>
>>
>
>
>

Neil,

I have attached code to draw the arrowhead.

-Ben



On May 13, 2015, at 7:44 PM, Neil Girdhar <mis...@gm...> wrote:

> Do you have the code that you used to draw the arrowhead?  I'm up to date now on the development workflow (http://matplotlib.org/devel/gitwash/development_workflow.html), so I'm ready to start working.
> 
> Thanks,
> 
> Neil
> 
> On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn <bre...@gm...> wrote:
> Yes, I fully agree that we need to unify the many different ways to draw arrows.  
> 
> Neil, in case an example would be helpful for you, I have attached a module that includes a custom arrowhead class.  The arrowhead class works with the with the ax.annotate() method.  (I like the annotate method because it allows me to easily mix and match coordinate systems for arrow placement.)  As you can see in the attached pdf, the custom arrowhead doesn't include fancy Bezier curves, but that could be added.
> 
> -Ben
> 
> 
> 
> On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:
> 
>> The other thing that should be done is to unify the (I think 7?!?) unique ways to draw arrows in mpl.
>> 
>> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...> wrote:
>> Yes, I just noticed that as well.  That's how the tikz pgf code looks (a sequence of line_to and curve_to commands and so on) so it should be easy to port over the various shapes.
>> 
>> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...> wrote:
>> On 2015/05/13 10:12 AM, Neil Girdhar wrote:
>> If you want to make arrowheads look at all decent, they really need to
>> be enclosed in Bezier curves.  See the diagram here:
>> 
>> Mpl paths support Bezier curves.
>> http://matplotlib.org/api/path_api.html?highlight=bezier
>> 
>> 
>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>> 
>> The first two look like garbage.  The last one is the only one that
>> looks good imho.
>> 
>> That depends on the application, and the observer.
>> 
>> Sure, but I may as well port them all of the tikz arrowheads over since most of the work would be figuring out how to do it.
>>  
>> 
>> 
>> Eric
>> 
>> 
>> Best,
>> 
>> Neil
>> 
>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>> <mailto:ef...@ha...>> wrote:
>> 
>>     On 2015/05/13 9:36 AM, Neil Girdhar wrote:
>> 
>>         I don't know matplotlib well enough (yet) to know what the
>>         change would
>>         consist of.
>> 
>>         I suggest you take a look at the beautiful tikz manual:
>>         http://pgf.sourceforge.net/pgf_CVS.pdf
>> 
>> 
>>     Very helpful, thank you.
>> 
>> 
>>         The arrows.meta on page 201–212 are really well-designed and
>>         beautiful.
>> 
>>         Compare this with matplotlib's custom arrows:
>>         http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>> 
>>         How do I make tikz's arrowheads available for all backends?
>> 
>> 
>>     My guess offhand is that this is a matter of using the mpl API.  I
>>     don't think we would want to add all of these types and options to
>>     the mpl core; but a toolkit might be ideal for this.  The mpl API,
>>     which generates the same results for all backends, is quite complete
>>     and flexible.  Things like arrowheads are Patch objects, and you can
>>     specify any path you want.  The main trick is figuring out how to
>>     handle transforms--what kind of coordinates should the path be
>>     specifying?  How should things scale as a figure is reshaped and
>>     resized?
>> 
>>     For many of these types you could also use mpl Line2D objects, for
>>     which several properties including cap style can be specified.  Not
>>     all of the TikZ options would be available, but perhaps enough.
>> 
>>     Eric
>> 
>> 
>> 
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud 
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
> 
> 
> 

Do you have the code that you used to draw the arrowhead?  I'm up to date
now on the development workflow (
http://matplotlib.org/devel/gitwash/development_workflow.html), so I'm
ready to start working.

Thanks,

Neil

On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn <bre...@gm...>
wrote:

> Yes, I fully agree that we need to unify the many different ways to draw
> arrows.
>
> Neil, in case an example would be helpful for you, I have attached a
> module that includes a custom arrowhead class.  The arrowhead class works
> with the with the ax.annotate() method.  (I like the annotate method
> because it allows me to easily mix and match coordinate systems for arrow
> placement.)  As you can see in the attached pdf, the custom arrowhead
> doesn't include fancy Bezier curves, but that could be added.
>
> -Ben
>
>
>
> On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:
>
> The other thing that should be done is to unify the (I think 7?!?) unique
> ways to draw arrows in mpl.
>
> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...>
> wrote:
>
>> Yes, I just noticed that as well.  That's how the tikz pgf code looks (a
>> sequence of line_to and curve_to commands and so on) so it should be easy
>> to port over the various shapes.
>>
>> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...> wrote:
>>
>>> On 2015/05/13 10:12 AM, Neil Girdhar wrote:
>>>
>>>> If you want to make arrowheads look at all decent, they really need to
>>>> be enclosed in Bezier curves.  See the diagram here:
>>>>
>>>
>>> Mpl paths support Bezier curves.
>>> http://matplotlib.org/api/path_api.html?highlight=bezier
>>>
>>>
>>>>
>>>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>>>
>>>> The first two look like garbage.  The last one is the only one that
>>>> looks good imho.
>>>>
>>>
>>> That depends on the application, and the observer.
>>
>>
>> Sure, but I may as well port them all of the tikz arrowheads over since
>> most of the work would be figuring out how to do it.
>>
>>
>>>
>>>
>>> Eric
>>>
>>>
>>>> Best,
>>>>
>>>> Neil
>>>>
>>>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>>>> <mailto:ef...@ha...>> wrote:
>>>>
>>>>     On 2015/05/13 9:36 AM, Neil Girdhar wrote:
>>>>
>>>>         I don't know matplotlib well enough (yet) to know what the
>>>>         change would
>>>>         consist of.
>>>>
>>>>         I suggest you take a look at the beautiful tikz manual:
>>>>         http://pgf.sourceforge.net/pgf_CVS.pdf
>>>>
>>>>
>>>>     Very helpful, thank you.
>>>>
>>>>
>>>>         The arrows.meta on page 201–212 are really well-designed and
>>>>         beautiful.
>>>>
>>>>         Compare this with matplotlib's custom arrows:
>>>>
>>>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>>>
>>>>         How do I make tikz's arrowheads available for all backends?
>>>>
>>>>
>>>>     My guess offhand is that this is a matter of using the mpl API.  I
>>>>     don't think we would want to add all of these types and options to
>>>>     the mpl core; but a toolkit might be ideal for this.  The mpl API,
>>>>     which generates the same results for all backends, is quite complete
>>>>     and flexible.  Things like arrowheads are Patch objects, and you can
>>>>     specify any path you want.  The main trick is figuring out how to
>>>>     handle transforms--what kind of coordinates should the path be
>>>>     specifying?  How should things scale as a figure is reshaped and
>>>>     resized?
>>>>
>>>>     For many of these types you could also use mpl Line2D objects, for
>>>>     which several properties including cap style can be specified.  Not
>>>>     all of the TikZ options would be available, but perhaps enough.
>>>>
>>>>     Eric
>>>>
>>>>
>>>>
>>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
>
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y_______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>
>
>
>

Wow, this looks great.

Thank you all of you so far for the quick responses and pointers.

I've already done many diagrams in Python-generated TikZ, which I want to
port over to pure Python.  They are basically variants of this:
http://www.texample.net/tikz/examples/graph/ .  Do you think this will be
possible?  That is, drawing nodes with labels inside and then anchoring the
arrows to the edges of the nodes?

With respect to the unification of arrow types, would you be able to point
me to which files or methods in the source they are based on?  I would like
to familiarize myself with all of them before I make a proposal of what I
intend to do.

Thanks,

Neil

On Wed, May 13, 2015 at 9:10 PM, Benjamin Reedlunn <bre...@gm...>
wrote:

> Yes, I fully agree that we need to unify the many different ways to draw
> arrows.
>
> Neil, in case an example would be helpful for you, I have attached a
> module that includes a custom arrowhead class.  The arrowhead class works
> with the with the ax.annotate() method.  (I like the annotate method
> because it allows me to easily mix and match coordinate systems for arrow
> placement.)  As you can see in the attached pdf, the custom arrowhead
> doesn't include fancy Bezier curves, but that could be added.
>
> -Ben
>
>
>
> On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:
>
> The other thing that should be done is to unify the (I think 7?!?) unique
> ways to draw arrows in mpl.
>
> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...>
> wrote:
>
>> Yes, I just noticed that as well.  That's how the tikz pgf code looks (a
>> sequence of line_to and curve_to commands and so on) so it should be easy
>> to port over the various shapes.
>>
>> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...> wrote:
>>
>>> On 2015/05/13 10:12 AM, Neil Girdhar wrote:
>>>
>>>> If you want to make arrowheads look at all decent, they really need to
>>>> be enclosed in Bezier curves.  See the diagram here:
>>>>
>>>
>>> Mpl paths support Bezier curves.
>>> http://matplotlib.org/api/path_api.html?highlight=bezier
>>>
>>>
>>>>
>>>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>>>
>>>> The first two look like garbage.  The last one is the only one that
>>>> looks good imho.
>>>>
>>>
>>> That depends on the application, and the observer.
>>
>>
>> Sure, but I may as well port them all of the tikz arrowheads over since
>> most of the work would be figuring out how to do it.
>>
>>
>>>
>>>
>>> Eric
>>>
>>>
>>>> Best,
>>>>
>>>> Neil
>>>>
>>>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>>>> <mailto:ef...@ha...>> wrote:
>>>>
>>>>     On 2015/05/13 9:36 AM, Neil Girdhar wrote:
>>>>
>>>>         I don't know matplotlib well enough (yet) to know what the
>>>>         change would
>>>>         consist of.
>>>>
>>>>         I suggest you take a look at the beautiful tikz manual:
>>>>         http://pgf.sourceforge.net/pgf_CVS.pdf
>>>>
>>>>
>>>>     Very helpful, thank you.
>>>>
>>>>
>>>>         The arrows.meta on page 201–212 are really well-designed and
>>>>         beautiful.
>>>>
>>>>         Compare this with matplotlib's custom arrows:
>>>>
>>>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>>>
>>>>         How do I make tikz's arrowheads available for all backends?
>>>>
>>>>
>>>>     My guess offhand is that this is a matter of using the mpl API.  I
>>>>     don't think we would want to add all of these types and options to
>>>>     the mpl core; but a toolkit might be ideal for this.  The mpl API,
>>>>     which generates the same results for all backends, is quite complete
>>>>     and flexible.  Things like arrowheads are Patch objects, and you can
>>>>     specify any path you want.  The main trick is figuring out how to
>>>>     handle transforms--what kind of coordinates should the path be
>>>>     specifying?  How should things scale as a figure is reshaped and
>>>>     resized?
>>>>
>>>>     For many of these types you could also use mpl Line2D objects, for
>>>>     which several properties including cap style can be specified.  Not
>>>>     all of the TikZ options would be available, but perhaps enough.
>>>>
>>>>     Eric
>>>>
>>>>
>>>>
>>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
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>> _______________________________________________
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>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>
> ------------------------------------------------------------------------------
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> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
>
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>

Yes, I fully agree that we need to unify the many different ways to draw arrows.  

Neil, in case an example would be helpful for you, I have attached a module that includes a custom arrowhead class.  The arrowhead class works with the with the ax.annotate() method.  (I like the annotate method because it allows me to easily mix and match coordinate systems for arrow placement.)  As you can see in the attached pdf, the custom arrowhead doesn't include fancy Bezier curves, but that could be added.

-Ben

On May 13, 2015, at 2:54 PM, Thomas Caswell <tca...@gm...> wrote:

> The other thing that should be done is to unify the (I think 7?!?) unique ways to draw arrows in mpl.
> 
> On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...> wrote:
> Yes, I just noticed that as well.  That's how the tikz pgf code looks (a sequence of line_to and curve_to commands and so on) so it should be easy to port over the various shapes.
> 
> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...> wrote:
> On 2015/05/13 10:12 AM, Neil Girdhar wrote:
> If you want to make arrowheads look at all decent, they really need to
> be enclosed in Bezier curves.  See the diagram here:
> 
> Mpl paths support Bezier curves.
> http://matplotlib.org/api/path_api.html?highlight=bezier
> 
> 
> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
> 
> The first two look like garbage.  The last one is the only one that
> looks good imho.
> 
> That depends on the application, and the observer.
> 
> Sure, but I may as well port them all of the tikz arrowheads over since most of the work would be figuring out how to do it.
>  
> 
> 
> Eric
> 
> 
> Best,
> 
> Neil
> 
> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
> <mailto:ef...@ha...>> wrote:
> 
>     On 2015/05/13 9:36 AM, Neil Girdhar wrote:
> 
>         I don't know matplotlib well enough (yet) to know what the
>         change would
>         consist of.
> 
>         I suggest you take a look at the beautiful tikz manual:
>         http://pgf.sourceforge.net/pgf_CVS.pdf
> 
> 
>     Very helpful, thank you.
> 
> 
>         The arrows.meta on page 201–212 are really well-designed and
>         beautiful.
> 
>         Compare this with matplotlib's custom arrows:
>         http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
> 
>         How do I make tikz's arrowheads available for all backends?
> 
> 
>     My guess offhand is that this is a matter of using the mpl API.  I
>     don't think we would want to add all of these types and options to
>     the mpl core; but a toolkit might be ideal for this.  The mpl API,
>     which generates the same results for all backends, is quite complete
>     and flexible.  Things like arrowheads are Patch objects, and you can
>     specify any path you want.  The main trick is figuring out how to
>     handle transforms--what kind of coordinates should the path be
>     specifying?  How should things scale as a figure is reshaped and
>     resized?
> 
>     For many of these types you could also use mpl Line2D objects, for
>     which several properties including cap style can be specified.  Not
>     all of the TikZ options would be available, but perhaps enough.
> 
>     Eric
> 
> 
> 
> ------------------------------------------------------------------------------
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> Widest out-of-the-box monitoring support with 50+ applications
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> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
> ------------------------------------------------------------------------------
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> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
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Fascinating! Can you "unpack" (heh) that error for us mere mortals? In
particular:

- never seen that "or" syntax before... Is it coercing both expressions as
bool, or is it evaluating to left if bool(left) evaluates to True, else to
right?
- Why do you expect the second expression to work? Is ** supposed to have
lower preference than "or"? (Which seems weird to me.)

Thanks!

Juan.

On Thu, May 14, 2015 at 5:08 AM, Thomas Caswell <tca...@gm...> wrote:

>
> The failures on python nightly are currently due to a bug in python (
> http://bugs.python.org/issue24176)
>
> Tom
>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>
>

The other thing that should be done is to unify the (I think 7?!?) unique
ways to draw arrows in mpl.

On Wed, May 13, 2015 at 4:52 PM Neil Girdhar <mis...@gm...> wrote:

> Yes, I just noticed that as well.  That's how the tikz pgf code looks (a
> sequence of line_to and curve_to commands and so on) so it should be easy
> to port over the various shapes.
>
> On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...> wrote:
>
>> On 2015/05/13 10:12 AM, Neil Girdhar wrote:
>>
>>> If you want to make arrowheads look at all decent, they really need to
>>> be enclosed in Bezier curves.  See the diagram here:
>>>
>>
>> Mpl paths support Bezier curves.
>> http://matplotlib.org/api/path_api.html?highlight=bezier
>>
>>
>>>
>>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>>
>>> The first two look like garbage.  The last one is the only one that
>>> looks good imho.
>>>
>>
>> That depends on the application, and the observer.
>
>
> Sure, but I may as well port them all of the tikz arrowheads over since
> most of the work would be figuring out how to do it.
>
>
>>
>>
>> Eric
>>
>>
>>> Best,
>>>
>>> Neil
>>>
>>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>>> <mailto:ef...@ha...>> wrote:
>>>
>>>     On 2015/05/13 9:36 AM, Neil Girdhar wrote:
>>>
>>>         I don't know matplotlib well enough (yet) to know what the
>>>         change would
>>>         consist of.
>>>
>>>         I suggest you take a look at the beautiful tikz manual:
>>>         http://pgf.sourceforge.net/pgf_CVS.pdf
>>>
>>>
>>>     Very helpful, thank you.
>>>
>>>
>>>         The arrows.meta on page 201–212 are really well-designed and
>>>         beautiful.
>>>
>>>         Compare this with matplotlib's custom arrows:
>>>
>>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>>
>>>         How do I make tikz's arrowheads available for all backends?
>>>
>>>
>>>     My guess offhand is that this is a matter of using the mpl API.  I
>>>     don't think we would want to add all of these types and options to
>>>     the mpl core; but a toolkit might be ideal for this.  The mpl API,
>>>     which generates the same results for all backends, is quite complete
>>>     and flexible.  Things like arrowheads are Patch objects, and you can
>>>     specify any path you want.  The main trick is figuring out how to
>>>     handle transforms--what kind of coordinates should the path be
>>>     specifying?  How should things scale as a figure is reshaped and
>>>     resized?
>>>
>>>     For many of these types you could also use mpl Line2D objects, for
>>>     which several properties including cap style can be specified.  Not
>>>     all of the TikZ options would be available, but perhaps enough.
>>>
>>>     Eric
>>>
>>>
>>>
>>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>

Yes, I just noticed that as well.  That's how the tikz pgf code looks (a
sequence of line_to and curve_to commands and so on) so it should be easy
to port over the various shapes.

On Wed, May 13, 2015 at 4:49 PM, Eric Firing <ef...@ha...> wrote:

> On 2015/05/13 10:12 AM, Neil Girdhar wrote:
>
>> If you want to make arrowheads look at all decent, they really need to
>> be enclosed in Bezier curves.  See the diagram here:
>>
>
> Mpl paths support Bezier curves.
> http://matplotlib.org/api/path_api.html?highlight=bezier
>
>
>>
>> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>>
>> The first two look like garbage.  The last one is the only one that
>> looks good imho.
>>
>
> That depends on the application, and the observer.


Sure, but I may as well port them all of the tikz arrowheads over since
most of the work would be figuring out how to do it.


>
>
> Eric
>
>
>> Best,
>>
>> Neil
>>
>> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
>> <mailto:ef...@ha...>> wrote:
>>
>>     On 2015/05/13 9:36 AM, Neil Girdhar wrote:
>>
>>         I don't know matplotlib well enough (yet) to know what the
>>         change would
>>         consist of.
>>
>>         I suggest you take a look at the beautiful tikz manual:
>>         http://pgf.sourceforge.net/pgf_CVS.pdf
>>
>>
>>     Very helpful, thank you.
>>
>>
>>         The arrows.meta on page 201–212 are really well-designed and
>>         beautiful.
>>
>>         Compare this with matplotlib's custom arrows:
>>
>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>
>>         How do I make tikz's arrowheads available for all backends?
>>
>>
>>     My guess offhand is that this is a matter of using the mpl API.  I
>>     don't think we would want to add all of these types and options to
>>     the mpl core; but a toolkit might be ideal for this.  The mpl API,
>>     which generates the same results for all backends, is quite complete
>>     and flexible.  Things like arrowheads are Patch objects, and you can
>>     specify any path you want.  The main trick is figuring out how to
>>     handle transforms--what kind of coordinates should the path be
>>     specifying?  How should things scale as a figure is reshaped and
>>     resized?
>>
>>     For many of these types you could also use mpl Line2D objects, for
>>     which several properties including cap style can be specified.  Not
>>     all of the TikZ options would be available, but perhaps enough.
>>
>>     Eric
>>
>>
>>
>

On 2015/05/13 10:12 AM, Neil Girdhar wrote:
> If you want to make arrowheads look at all decent, they really need to
> be enclosed in Bezier curves.  See the diagram here:

Mpl paths support Bezier curves.
http://matplotlib.org/api/path_api.html?highlight=bezier

>
> http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965
>
> The first two look like garbage.  The last one is the only one that
> looks good imho.

That depends on the application, and the observer.

Eric

>
> Best,
>
> Neil
>
> On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...
> <mailto:ef...@ha...>> wrote:
>
>     On 2015/05/13 9:36 AM, Neil Girdhar wrote:
>
>         I don't know matplotlib well enough (yet) to know what the
>         change would
>         consist of.
>
>         I suggest you take a look at the beautiful tikz manual:
>         http://pgf.sourceforge.net/pgf_CVS.pdf
>
>
>     Very helpful, thank you.
>
>
>         The arrows.meta on page 201–212 are really well-designed and
>         beautiful.
>
>         Compare this with matplotlib's custom arrows:
>         http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>
>         How do I make tikz's arrowheads available for all backends?
>
>
>     My guess offhand is that this is a matter of using the mpl API.  I
>     don't think we would want to add all of these types and options to
>     the mpl core; but a toolkit might be ideal for this.  The mpl API,
>     which generates the same results for all backends, is quite complete
>     and flexible.  Things like arrowheads are Patch objects, and you can
>     specify any path you want.  The main trick is figuring out how to
>     handle transforms--what kind of coordinates should the path be
>     specifying?  How should things scale as a figure is reshaped and
>     resized?
>
>     For many of these types you could also use mpl Line2D objects, for
>     which several properties including cap style can be specified.  Not
>     all of the TikZ options would be available, but perhaps enough.
>
>     Eric
>
>

If you want to make arrowheads look at all decent, they really need to be
enclosed in Bezier curves.  See the diagram here:

http://tex.stackexchange.com/questions/150289/how-do-you-accomplish-stealth-with-the-new-arrows-meta/230965#230965

The first two look like garbage.  The last one is the only one that looks
good imho.

Best,

Neil

On Wed, May 13, 2015 at 4:09 PM, Eric Firing <ef...@ha...> wrote:

> On 2015/05/13 9:36 AM, Neil Girdhar wrote:
>
>> I don't know matplotlib well enough (yet) to know what the change would
>> consist of.
>>
>> I suggest you take a look at the beautiful tikz manual:
>> http://pgf.sourceforge.net/pgf_CVS.pdf
>>
>
> Very helpful, thank you.
>
>
>> The arrows.meta on page 201–212 are really well-designed and beautiful.
>>
>> Compare this with matplotlib's custom arrows:
>>
>> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>>
>> How do I make tikz's arrowheads available for all backends?
>>
>>
> My guess offhand is that this is a matter of using the mpl API.  I don't
> think we would want to add all of these types and options to the mpl core;
> but a toolkit might be ideal for this.  The mpl API, which generates the
> same results for all backends, is quite complete and flexible.  Things like
> arrowheads are Patch objects, and you can specify any path you want.  The
> main trick is figuring out how to handle transforms--what kind of
> coordinates should the path be specifying?  How should things scale as a
> figure is reshaped and resized?
>
> For many of these types you could also use mpl Line2D objects, for which
> several properties including cap style can be specified.  Not all of the
> TikZ options would be available, but perhaps enough.
>
> Eric
>
>

On 2015/05/13 9:36 AM, Neil Girdhar wrote:
> I don't know matplotlib well enough (yet) to know what the change would
> consist of.
>
> I suggest you take a look at the beautiful tikz manual:
> http://pgf.sourceforge.net/pgf_CVS.pdf

Very helpful, thank you.

>
> The arrows.meta on page 201–212 are really well-designed and beautiful.
>
> Compare this with matplotlib's custom arrows:
> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>
> How do I make tikz's arrowheads available for all backends?
>

My guess offhand is that this is a matter of using the mpl API.  I don't 
think we would want to add all of these types and options to the mpl 
core; but a toolkit might be ideal for this.  The mpl API, which 
generates the same results for all backends, is quite complete and 
flexible.  Things like arrowheads are Patch objects, and you can specify 
any path you want.  The main trick is figuring out how to handle 
transforms--what kind of coordinates should the path be specifying?  How 
should things scale as a figure is reshaped and resized?

For many of these types you could also use mpl Line2D objects, for which 
several properties including cap style can be specified.  Not all of the 
TikZ options would be available, but perhaps enough.

Eric

Just to point out, matplotlib does have a fairly new PGF backend. Perhaps
you might want to look at that and see where the TikZ library might fit in
with that?

Cheers!
Ben Root

On Wed, May 13, 2015 at 3:36 PM, Neil Girdhar <mis...@gm...> wrote:

> I don't know matplotlib well enough (yet) to know what the change would
> consist of.
>
> I suggest you take a look at the beautiful tikz manual:
> http://pgf.sourceforge.net/pgf_CVS.pdf
>
> The arrows.meta on page 201–212 are really well-designed and beautiful.
>
> Compare this with matplotlib's custom arrows:
> http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate
>
> How do I make tikz's arrowheads available for all backends?
>
>
>
> On Wed, May 13, 2015 at 2:55 PM, Eric Firing <ef...@ha...> wrote:
>
>> On 2015/05/13 12:39 AM, Neil Girdhar wrote:
>> > TikZ is an extremely well-designed library for generating professional
>> > figures within the cumbersome TeX framework.  Currently, my work flow is
>> > to generate TikZ code using Python.  The TikZ is compiled into PDFs,
>> > which are then included in my LaTeX files.  I would like to work
>> > entirely in Python.
>> >
>> > This means that I want to incorporate TikZ's features into matplotlib.
>> > I want to start with custom pgf arrowheads.  Will this be possible.
>> > What is the process from feature idea to pull request that I would have
>> > to go through?
>>
>> You're on the right track by raising the idea here.  Depending on how
>> complicated the idea is, the next step after some mailing list
>> discussion could be either a MEP or a PR; but personally I would prefer
>> to get a better picture of what you are talking about via this mailing
>> list first.
>>
>> Are you talking about adding high-level functionality that would be
>> applicable to all backends?  Can you give an example of what sorts of
>> changes would be required in mpl, and what they would accomplish?
>>
>> Eric
>>
>> >
>> > Best,
>> >
>> > Neil
>>
>>
>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>> _______________________________________________
>> Matplotlib-devel mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>>
>
>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>
>

I don't know matplotlib well enough (yet) to know what the change would
consist of.

I suggest you take a look at the beautiful tikz manual:
http://pgf.sourceforge.net/pgf_CVS.pdf

The arrows.meta on page 201–212 are really well-designed and beautiful.

Compare this with matplotlib's custom arrows:
http://stackoverflow.com/questions/16968007/custom-arrow-style-for-matplotlib-pyplot-annotate

How do I make tikz's arrowheads available for all backends?



On Wed, May 13, 2015 at 2:55 PM, Eric Firing <ef...@ha...> wrote:

> On 2015/05/13 12:39 AM, Neil Girdhar wrote:
> > TikZ is an extremely well-designed library for generating professional
> > figures within the cumbersome TeX framework.  Currently, my work flow is
> > to generate TikZ code using Python.  The TikZ is compiled into PDFs,
> > which are then included in my LaTeX files.  I would like to work
> > entirely in Python.
> >
> > This means that I want to incorporate TikZ's features into matplotlib.
> > I want to start with custom pgf arrowheads.  Will this be possible.
> > What is the process from feature idea to pull request that I would have
> > to go through?
>
> You're on the right track by raising the idea here.  Depending on how
> complicated the idea is, the next step after some mailing list
> discussion could be either a MEP or a PR; but personally I would prefer
> to get a better picture of what you are talking about via this mailing
> list first.
>
> Are you talking about adding high-level functionality that would be
> applicable to all backends?  Can you give an example of what sorts of
> changes would be required in mpl, and what they would accomplish?
>
> Eric
>
> >
> > Best,
> >
> > Neil
>
>
>
> ------------------------------------------------------------------------------
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The failures on python nightly are currently due to a bug in python (
http://bugs.python.org/issue24176)

Tom

On 2015/05/13 12:39 AM, Neil Girdhar wrote:
> TikZ is an extremely well-designed library for generating professional
> figures within the cumbersome TeX framework.  Currently, my work flow is
> to generate TikZ code using Python.  The TikZ is compiled into PDFs,
> which are then included in my LaTeX files.  I would like to work
> entirely in Python.
>
> This means that I want to incorporate TikZ's features into matplotlib.
> I want to start with custom pgf arrowheads.  Will this be possible.
> What is the process from feature idea to pull request that I would have
> to go through?

You're on the right track by raising the idea here.  Depending on how 
complicated the idea is, the next step after some mailing list 
discussion could be either a MEP or a PR; but personally I would prefer 
to get a better picture of what you are talking about via this mailing 
list first.

Are you talking about adding high-level functionality that would be 
applicable to all backends?  Can you give an example of what sorts of 
changes would be required in mpl, and what they would accomplish?

Eric

>
> Best,
>
> Neil

TikZ is an extremely well-designed library for generating professional
figures within the cumbersome TeX framework.  Currently, my work flow is to
generate TikZ code using Python.  The TikZ is compiled into PDFs, which are
then included in my LaTeX files.  I would like to work entirely in Python.

This means that I want to incorporate TikZ's features into matplotlib.  I
want to start with custom pgf arrowheads.  Will this be possible.  What is
the process from feature idea to pull request that I would have to go
through?

Best,

Neil

Hi all,

I wanted to let the community know that we are currently hiring 3 full time
software engineers to work full time on Project Jupyter/IPython. These
positions will be in my group at Cal Poly in San Luis Obispo, CA. We are
looking for frontend and backend software engineers with lots of
Python/JavaScript experience and a passion for open source software. The
details can be found here:

https://www.calpolycorporationjobs.org/postings/736

This is an unusual opportunity in a couple of respects:

* These positions will allow you to work on open source software full time
- not as a X% side project (aka weekends and evenings).
* These are fully benefited positions (CA state retirement, health care,
etc.)
* You will get to work and live in San Luis Obispo, one of the nicest
places on earth. We are minutes from the beach, have perfect year-round
weather and are close to both the Bay Area and So Cal.

I am more than willing to talk to any who interested in these positions.

Cheers,

Brian

-- 
Brian E. Granger
Cal Poly State University, San Luis Obispo
@ellisonbg on Twitter and GitHub
bgr...@ca... and ell...@gm...

I think that so long as you maintain the mapping of 'manager' to be 'gui
element holding the Figure' (rather than 'gui window holding figure')
numbering the managers should be ok.   That is, the tabs are the managers
and the multi-figure windows are a layer above the managers.

The notion of 'figure number' is very thoroughly a pyplot/figure manager
idea I am -1 on pushing that logic down in to the Figure class.

Tom

On Wed, May 6, 2015 at 4:42 PM Eric Firing <ef...@ha...> wrote:

> On 2015/05/06 9:19 AM, Federico Ariza wrote:
> > Hello
> >
> > Is there any reason why the "num" property is assigned to the manager
> > and not to the figure?
>
> I think this is because the figure is at the object-oriented API level.
>   The manager is in the pyplot state-machine level.
>
> > Pyplot.gcf is to get the "current figure" not the "current manager".
>
> It is really "get current managed figure", combined with the original
> idea that the manager is the pyplot layer on top of the figure, with one
> manager per figure.  The "current" concept comes from the state machine.
>
> >
> > In general this is not a problem. But I'm working on MEP23 where one
> > manager can contain several figures. And it would be pretty nice if I
> > could reference the figures by that number not the managers.
> >
> > A priori, do you see any problem with a PR changing that?
>
> It seems like it could work--but what will it do to existing user code?
>
> Eric
>
> >
> > Thanks
> > Federico
> >
> >
> >
> >
> ------------------------------------------------------------------------------
> > One dashboard for servers and applications across Physical-Virtual-Cloud
> > Widest out-of-the-box monitoring support with 50+ applications
> > Performance metrics, stats and reports that give you Actionable Insights
> > Deep dive visibility with transaction tracing using APM Insight.
> > http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> >
> >
> >
> > _______________________________________________
> > Matplotlib-devel mailing list
> > Mat...@li...
> > https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
> >
>
>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-devel mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
>

For what it's worth, there are matplotlib, scipy, and IPython channels on
the freenode IRC network.  I often answer questions there.

On Monday, May 4, 2015, Bryan Van de Ven <br...@co...> wrote:

> We've thought about gitter as well, personally my (slight) preference for
> Slack is that it does not require a GH account, and also, there is a nice
> OSS heroku app that provides a really nice "self-invite" button that shows
> how many users are on, too. You can see it on our test docs deploy:
>
>         http://bokeh.pydata.org/en/test/index.html
>
> That said it is probably six of one, half dozen of the other. I'm not
> categorically opposed to looking into gitter some more.
>
> My hope (and intent) is really to have this as a place for users to
> congregate and self-support. We do intend to monitor, to the extent we can,
> but like you there is precious little bandwidth form core devs.
>
> Bryan
>
>
> > On May 4, 2015, at 11:45 AM, Thomas Caswell <tca...@gm...
> <javascript:;>> wrote:
> >
> > That sounds reasonable to me.  My only concern is getting enough (any?)
> bandwidth from enough of the core mpl developers.
> >
> > IPython and scikit image both have gitter rooms running that seem to
> working well for them as well, is there any reason to go with slack over
> gitter?
> >
> > Tom
> >
> > ---------- Forwarded message ---------
> > From: Bryan Van de Ven <br...@co... <javascript:;>>
> > Date: Mon, May 4, 2015 at 11:44 AM
> > Subject: python data vis Slack channels?
> > To: Michael Droettboom <md...@st... <javascript:;>>, <
> tca...@gm... <javascript:;>>
> >
> >
> > Hi guys,
> >
> > We have been experimenting/toying with the idea of using a free Slack
> channel to provide a place for casual Bokeh user interactions. It occurred
> that it might be nice to have a single "pyvis.slack.com", that has
> channels for several OSS python vis libraries in one place. Would you have
> any interest in a #matplotlib channel there? If there is a better place to
> submit this proposal, please let me know.
> >
> > Regards,
> >
> > Bryan Van de Ven
> >
>
>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
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