matplotlib-users Mailing List for matplotlib

thanks for all the responses. still finding it very confusing!! but got it
to work (without having to import in the loop).
I used:
from datetime import datetime as dt

but I also had to call:
from datetime import timedelta

and now it seems to work nicely. thank you


On Fri, Apr 20, 2012 at 3:36 AM, Benjamin Root <ben...@ou...> wrote:

>
>
> On Thu, Apr 19, 2012 at 1:21 PM, Goyo <goy...@gm...> wrote:
>
>> El día 19 de abril de 2012 05:31, questions anon
>> <que...@gm...> escribió:
>> > Thank you, I was able to get it to work but only if I imported datetime
>> > within the loop, otherwise I ended up with the
>> > AttributeError: type object 'datetime.datetime' has no attribute
>> 'datetime'
>> > and if I added 'import datetime' at the top of my script it had an error
>> > where I loop through combining each month
>> > "    stop_month = datetime(2011, 03, 01)
>> > TypeError: 'module' object is not callable"
>>
>> If you can write a standalone, minimal executable script which
>> reproduces the problem I'll take a look. Send it as an attachement and
>> add sample data files if necessary.
>>
>> Goyo
>>
>>
> The issue is that there is a slight mixup in namespaces.  There is a
> module called datetime, and that module contains a class object called
> datetime.  So, if your imports at the top are "import datetime", then all
> your module-related stuff need to be prepended with "datetime.". But, if
> your imports at the top are "from datetime import datetime", then you can
> use the object freely, but you can't use anything else from the module
> unless you also import it.
>
> Here is the tricky part.  In your code, you did the following:
>
> from datetime import datetime
>
> If you then did:
>
> import datetime
>
> depending on the order the two were, one would overwrite the other.  You
> can only have one thing called "datetime".  Personally, I would do one of
> two things:
>
> import datetime as dt
>
> and use "dt.datetime()" to create datetime objects as well as call
> functions like "dt.strftime()". Or, do
>
> from datetime import datetime, date, timedelta, strftime
>
> and get replace calls like "datetime.datetime()" and "datetime.strftime()"
> with just "datetime()" and "strftime()".
>
> I hope that clears things up.  Namespaces are a honking good idea, but
> having objects be the same exact name as a module gets confusing very
> easily.
>
> Cheers!
> Ben Root
>
>

On 04/21/2012 06:35 PM, Ariel Rokem wrote:
>
>
> ParseFatalException: Expected end of math '$'
> $rac{S}{S_0}$ (at char 0), (line:1, col:1)
>
> Should this have been resolved already? Does it relate to this issue?
>
> https://github.com/matplotlib/matplotlib/issues/659
>
The improved error messages are not on the 1.1.x branch.  They will be 
in the first of the 1.2.x series.

In this particular case, however, you seem to be running into a problem 
by not using raw strings.  The "\f" in "\frac" is getting converted by 
Python into a formfeed character.  Use r"\frac{S}{S_0}" and you should 
have more luck.

Mike

In article 
<CAA...@ma...>,
 C M <cmp...@gm...> wrote:

> Trying to help a Mac friend running OSX 10.7 (Lion) easily set up to test
> scripts I send him, and have some questions:
> 
> 1) Can Matplotlib 1.1 run on the Python 2.7.2 version that comes with
> Lion?

Yes. You can easily build it yoursef as long as you have XCode 
installed: 

- Edit setupext.py so that the list of values for "darwin" is 
['/usr/local', '/usr', /usr/X11']
(and for a really vanilla build leave out /usr/local). (I have a pull 
request for this to be part of the standard distro, but I don't know if 
or when it will go in since not a big issue.)

Then do the usual:
% python setup.py build
% sudo python setup.py install

> 2) When is there expected to be an installer for Matplotlib 1.1 for OSX
> 10.7?

There is one, but like all the matplotlib (and numpy and scipy) official 
binaries it uses python.org's python, not Apple's.

To go this route install python.org's Python 2.7.2 for 10.6-and-later 
(which is 64-bit) and then install the official numpy and matpotlib 
binaries.

(It is a bit of a hassle to have to install a different python, but it 
has the advantage that you can freely upgrade python itself and packages 
without fear of breaking anything in the operating system.)

There are lots of other options: Enthought has a python installer that 
includes lots of useful scientific packages. ActiveState has an 
installer with a lot of packages available (though last I checked 
matplotlib was out of date, which quite surprised me). MacPorts and 
competing package managers make it easy to install packages.

Regards,

-- Russell

Sorry, I thougt I used the wrong address for mailing and resent. :'(

Hello list

matplotlib website says this mailing  is the prefered way to report
bug, so here I am :

System :
python ; 2.7.2+
matplotlib 1.1.0
ubuntu TLS amd64
matplotlib Backend : TkAgg


How to reproduce (on my pf)
Code Snippet :

######CODE

import matplotlib
import matplotlib.pyplot as p
import random
y = random.randint(0,10000000)
p.plot( [ int( y * ( 1 - 0.0006)) , y])
p.show()

######ENDCODE

Exected Result :
https://github.com/jul/pypi-stat/blob/master/why.png

Cause ?

It stinks something like a rounding error on the float.
If it also happens in Qt/Gtk backend it might be a matplotlib bug, if
it is only in Tk then it is either a Tk or a TkAgg bug.

Cheers,
-- 
Jul

Hello list

matplotlib website says this mailing  is the prefered way to report
bug, so here I am :

System :
python ; 2.7.2+
matplotlib 1.1.0
ubuntu TLS amd64
matplotlib Backend : TkAgg


How to reproduce (on my pf)
Code Snippet :

######CODE

import matplotlib
import matplotlib.pyplot as p
import random
y = random.randint(0,10000000)
p.plot( [ int( y * ( 1 - 0.0006)) , y])
p.show()

######ENDCODE

Exected Result :
https://github.com/jul/pypi-stat/blob/master/why.png

Cause ?

It stinks something like a rounding error on the float.
If it also happens in Qt/Gtk backend it might be a matplotlib bug, if
it is only in Tk then it is either a Tk or a TkAgg bug.

Cheers,
-- 
jul

Hi,

I managed to figure this out. I need to pass an init function to
FuncAnimation. Quoting from the MatPlotLib API documentation:

*init_func* is a function used to draw a clear frame. If not given, the
results of drawing from the first item in the frames sequence will be used.

So just in case someone has the same problem, here's the correct code:

import matplotlib
import numpy as np
from matplotlib.lines import Line2D
import matplotlib.pyplot as plt
import matplotlib.animation as animation

class Scope:
    def __init__(self, ax, maxt=10, dt=1):
        self.ax = ax
        self.dt = dt
        self.maxt = maxt
        self.tdata = [0]
        self.ydata = [0]
        self.line = Line2D(self.tdata, self.ydata, marker='o')
        self.ax.add_line(self.line)
        self.ax.set_ylim(0, 200)
        self.ax.set_xlim(0, self.maxt)
        self.ax.set_xlabel("Time(s)")
        self.ax.set_ylabel("Jitter Buffer Size(ms)",
color=self.line.get_color())

    def init(self):
        self.line.set_data([], [])
        return self.line,

    def update(self, y):
        lastt = self.tdata[-1]
        if lastt == self.tdata[0] + self.maxt: # reset the arrays
            self.tdata = [self.tdata[-1]]
            self.ydata = [self.ydata[-1]]
            self.ax.set_xlim(self.tdata[0], self.tdata[0] + self.maxt)
            self.ax.figure.canvas.draw()

        t = self.tdata[-1] + self.dt
        self.tdata.append(t)
        self.ydata.append(y)
        self.line.set_data(self.tdata, self.ydata)
        return self.line,

def emitter():
    while True:
        yield np.random.randint(0,200)

fig = plt.figure()
ax = fig.add_subplot(111)
scope = Scope(ax)

# pass a generator in "emitter" to produce data for the update func
ani = animation.FuncAnimation(fig, scope.update, emitter, interval=1000,
blit=True, init_func=scope.init)

plt.show()
Best Regards,
Clare.

Hi,

I'm trying to learn how to use FuncAnimation. I made some small
modifications to one of the matplotlib examples & tried it out, but I
encounter a problem. I'm trying to update a line plot every 1 sec & I have
my x-axis limit set to (0,10) initially. When the plot reaches x=10, I
change the x-axis limit to (10,20) & continue the plot from there. I found
that the 1st 2 seconds of the plot is always re-drawn in the 10th to 12th
seconds, 20th to 22nd seconds and so on. I don't understand what's going
on, so I hope someone here in this list can help me.

Just in case you don't understand what I mean, I've included the code below
so you'll have a better idea when you run the code:

import matplotlib
import numpy as np
from matplotlib.lines import Line2D
import matplotlib.pyplot as plt
import matplotlib.animation as animation
class Scope:
    def __init__(self, ax, maxt=10, dt=1):
        self.ax = ax
        self.dt = dt
        self.maxt = maxt
        self.tdata = [0]
        self.ydata = [0]
        self.line = Line2D(self.tdata, self.ydata, marker='o')
        self.ax.add_line(self.line)
        self.ax.set_ylim(0, 200)
        self.ax.set_xlim(0, self.maxt)
        self.ax.set_xlabel("Time(s)")
        self.ax.set_ylabel("Jitter Buffer Size(ms)",
color=self.line.get_color())
#        self.ax.yaxis.label.set_color(self.line.get_color())
    def update(self, y):
        lastt = self.tdata[-1]
        if lastt == self.tdata[0] + self.maxt: # reset the arrays
            self.tdata = [self.tdata[-1]]
            self.ydata = [self.ydata[-1]]
            self.ax.set_xlim(self.tdata[0], self.tdata[0] + self.maxt)
            self.ax.figure.canvas.draw()
        t = self.tdata[-1] + self.dt
        self.tdata.append(t)
        self.ydata.append(y)
        self.line.set_data(self.tdata, self.ydata)
        return self.line,

def emitter():
    while True:
        yield np.random.randint(0,200)
fig = plt.figure()
ax = fig.add_subplot(111)
scope = Scope(ax)
# pass a generator in "emitter" to produce data for the update func
ani = animation.FuncAnimation(fig, scope.update, emitter, interval=1000,
    blit=True)

plt.show()
Best Regards,
Clare.