matplotlib-users Mailing List for matplotlib

Hello,

I graph of weather data from a CGI script using the Agg backend only. The graph
is a common time vs. temperature 2D line plot. Since the graph plots
every n minutes, the lines on the graph tend to look pointed and not very
aesthetically pleasing (as many people have informed me.)
I did some research and found I needed to do curve fitting.

I'm trying to use 8th order polynomial fitting. I have found a sample on the
Web that shows how to use matplotlib to do a best-fit line from polyfit, but
I want a curve that follows the curve of weather temperature data.

I plot the data using a list of X-coordinates and a list of Y-coordinates.
I assume I can call polyfit with (x,y,8) for 8th order polynomial fitting.
However, I am not sure what to do with the results. I have tried to
translate the 1st order polyfit example for my needs but I don't think
I am using the polyfit data correctly.

Also, it has been suggested that a spline or Butterworth filter on the data
may yield more predictable results. I have found some of this functionality
in SciPy and a nifty module in a language called Octave. Would matplotlib
benefit from this?

Any assistance is much appreciated. I'm just starting out on this type of stuff
but it is fascinating to work with!

Thank you,

Brian

Kosta, 

> I'm trying to embed matplotlib on WX (which seems to work well for the 
> moment). I'd like to avoid the wx mainloop() by making it run in a 
> different thread than that of my main program.
> 
> The classical way of doing (using show() ) doesn't work. The
> first time, the figure becomes the main thread and my program
> stops running until I close the window. The second time I call
> it though, my program remains the main thread... Check the
> following code

Hmm, could you explain why you want to avoid the wx mainloop,
and what you mean by this. Do want wx to process events, right?

You say you're trying to embed matplotlib on WX, but the code
you posted doesn't do this.  It uses pylab, which creates a wx
App and runs its mainloop when you do show().  My guess is that
you're probably start getting the behavior you expect once that
auto-created wxapp is killed.

A simple answer would be to not use pylab, and just use a
matplotlib FigureCanvas with wx.  You'd have a mainloop then (I
don't see how you avoid that!!). You could start another thread
for non-GUI processing if you wanted, or *use* the mainloop's
events (timers or data-changing events) to update the plot.

Hope that helps,

--Matt

>>>>> "Jean-Michel" == Jean-Michel Philippe <jea...@ar...> writes:

    Jean-Michel> Yes I have but was a little bit disappointed since
    Jean-Michel> this nested expression fails (matplotlib 0.72):

    Jean-Michel> \rm{\acute{e}}

This was a parser bug in mathtext which is fixed in CVS.  Be sure and
let me know when you encounter these kinds of problems since they are
usually easy to fix

While I was at it, I also implemented unicode support for the *Agg and
PS backends :-)  If you have access to CVS, you may want to give it a
test drive.  See examples/unicode_demo.py.  CVS mirrors may lag.

    Jean-Michel> Believe me I would really be glad to participate to
    Jean-Michel> the matplotlib source code. Unfortunately I don't
    Jean-Michel> think I have the required skills (unless you know
    Jean-Michel> some introducing pages that could change my opinion?)
    Jean-Michel> and my company - a research centre - isn't mature
    Jean-Michel> enough to let us participate to open source :-(. It
    Jean-Michel> is even hard to make people accept open source
    Jean-Michel> software for everyday use... They don't feel secure
    Jean-Michel> if do not pay for!

If they are looking for someone to pay.... :-)


JDH

Jan,

On many lists, asking 'please help me' three times in under
twelve hours is liable to get you no help at all, and quite
possibly prevent people from helping you in the future.  

> could anyone show me how to incorporate this example on my GUI?
>
> what i want to do is to implement this in a wxPanel that is
> part of my wxFrame, but i am getting errors that says wxPanel
> instance has no attribute GetToolBar...

The embedding_in_wx*.py examples didn't help??  The code you
posted doesn't have a wxPanel or a wxFrame, so it's difficult to
say what the problem might be or what you actually want to do.

In general, you can put a FigureCanvasXXX on a wxPanel or
wxFrame.  A simple example putting a figure on a wxPanel is
below. Hope that helps,

--Matt

import wx
from matplotlib.numerix import arange, sin, pi
from matplotlib.figure import Figure
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg

class PlotPanel(wx.Panel):
    def __init__(self,parent=None):
        wx.Panel.__init__(self,parent,-1)
        self.fig = Figure((5,4),  75)
        self.canvas = FigureCanvasWxAgg(self,-1,self.fig)
        self.axes   = self.fig.add_axes([0.12,0.12,0.76,0.76])

        sizer = wx.BoxSizer(wx.VERTICAL)
        sizer.Add(self.canvas,1, wx.LEFT|wx.TOP)

        self.SetSizer(sizer) ;    self.Fit()
        
    def plot(self,x,y):
        self.axes.cla()
        self.axes.plot(x,y)

class PlotFrame(wx.Frame):
    def __init__(self,parent=None):
        wx.Frame.__init__(self,parent,-1,'Frame')
                                  
        self.plotpanel = PlotPanel(self)
        sizer = wx.BoxSizer(wx.VERTICAL)
        sizer.Add(wx.StaticText(self, -1 , ' WX Matplotlib example ')
                  ,0, wx.LEFT|wx.TOP)
        sizer.Add(self.plotpanel,1, wx.LEFT|wx.TOP)

        self.SetSizer(sizer) ;    self.Fit()

    def plot(self,x,y):
        self.plotpanel.plot(x,y)

if __name__ == '__main__':
    app = wx.PySimpleApp()
    frame = PlotFrame()
    x = arange(0,10.0,0.025)
    y = sin(x*pi/2)
    frame.plot(x,y)
    frame.Show()
    app.MainLoop()

>>>>> "Laurent" == Laurent THIOUDELLET <lau...@la...> writes:

    Laurent> The error is reproduced hereafter:

    Laurent> In file included from src/_gtkagg.cpp:8:
    Laurent> /usr/include/pygtk-2.0/pygobject.h:124: error: expected
    Laurent> `,' or `...' before "typename"
    Laurent> /usr/include/pygtk-2.0/pygobject.h:131: error: expected
    Laurent> `,' or `...' before "typename" In file included from

This is a pygtk bug, discussed here:

  http://matplotlib.sourceforge.net/faq.html#PYGTK24

Search the matplotlib-users archive at
http://sourceforge.net/mailarchive/forum.php?forum_id=33405 for
"typename" for more specific information.

JDH

>>>>> "Jessika" == Jessika Chumak <eli...@ya...> writes:

    Jessika> hours = HourLocator() minutes = MinuteLocator() timeFmt =
    Jessika> DateFormatter('%H:%M')

    Jessika> ax.xaxis.set_major_locator(hours)
    Jessika> ax.xaxis.set_minor_locator(minutes)
    Jessika> ax.xaxis.set_minor_formatter(timeFmt)

    Jessika> ax.autoscale_view()

    Jessika> Am I too far off target here?  Because I can't get it to
    Jessika> work.

    Jessika> I've also looked at the user's manual (5.4 example 2:
    Jessika> date ticking).  Could someone please point me in the
    Jessika> right direction or provide an example of how it _should_
    Jessika> be done?  Thank you in advance.

All of the date ticker locators accept ranges to indicate where you
want the ticks.  See, eg,
http://matplotlib.sourceforge.net/matplotlib.dates.html#MinuteLocator

To tick every 5 minutes, just give the range of minutes you want
ticked

  loc = MinuteLocator(range(5,60,5))  # don't tick on 0 and 60
  loc = MinuteLocator(range(0,61,5))  # tick on 0 and 60 as well

The default is to tick on every minute...

JDH

Hello all,


I am trying to install matplotlib for Python 2.3 under Linux (Mandrake 10.1 
AMD64) and the installation fails while trying to perform the build command.
I checked for the prerequisite and all the recommended packages seem to be 
correctly installed.

I am unable to understand the compilation error as it does not look like a 
trivial error (include file missing, library not reachable, ....) and as my 
C++ and Python skills are yet very weak.

The error is reproduced hereafter:

[root@TigerBox matplotlib-0.73.1]# python setup.py build
running build
running build_py
running build_ext
building 'matplotlib.backends._gtkagg' extension
creating build/temp.linux-x86_64-2.3
creating build/temp.linux-x86_64-2.3/src
creating build/temp.linux-x86_64-2.3/CXX
gcc -pthread -fno-strict-aliasing -DNDEBUG -O2 -pipe -Wall -g -fPIC 
-I/usr/local/include -I/usr/include -Isrc -Iagg22/include -I. 
-I/usr/local/include -I/usr/include -I/usr/local/include/freetype2 
-I/usr/include/freetype2 -Isrc/freetype2 -Iagg22/include/freetype2 
-I./freetype2 -I/usr/local/include/freetype2 -I/usr/include/freetype2 
-I/usr/local/include -I/usr/include -I/usr/include/pygtk-2.0 
-I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/gtk-2.0 
-I/usr/lib64/gtk-2.0/include -I/usr/X11R6/include -I/usr/include/atk-1.0 
-I/usr/include/pango-1.0 -I/usr/include/freetype2 
-I/usr/include/freetype2/freetype2 -I/usr/include/freetype2/freetype2/config 
-I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include 
-I/usr/include/python2.3 -c CXX/IndirectPythonInterface.cxx -o 
build/temp.linux-x86_64-2.3/CXX/IndirectPythonInterface.o
gcc -pthread -fno-strict-aliasing -DNDEBUG -O2 -pipe -Wall -g -fPIC 
-I/usr/local/include -I/usr/include -Isrc -Iagg22/include -I. 
-I/usr/local/include -I/usr/include -I/usr/local/include/freetype2 
-I/usr/include/freetype2 -Isrc/freetype2 -Iagg22/include/freetype2 
-I./freetype2 -I/usr/local/include/freetype2 -I/usr/include/freetype2 
-I/usr/local/include -I/usr/include -I/usr/include/pygtk-2.0 
-I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/gtk-2.0 
-I/usr/lib64/gtk-2.0/include -I/usr/X11R6/include -I/usr/include/atk-1.0 
-I/usr/include/pango-1.0 -I/usr/include/freetype2 
-I/usr/include/freetype2/freetype2 -I/usr/include/freetype2/freetype2/config 
-I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include 
-I/usr/include/python2.3 -c CXX/cxxextensions.c -o 
build/temp.linux-x86_64-2.3/CXX/cxxextensions.o
gcc -pthread -fno-strict-aliasing -DNDEBUG -O2 -pipe -Wall -g -fPIC 
-I/usr/local/include -I/usr/include -Isrc -Iagg22/include -I. 
-I/usr/local/include -I/usr/include -I/usr/local/include/freetype2 
-I/usr/include/freetype2 -Isrc/freetype2 -Iagg22/include/freetype2 
-I./freetype2 -I/usr/local/include/freetype2 -I/usr/include/freetype2 
-I/usr/local/include -I/usr/include -I/usr/include/pygtk-2.0 
-I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/gtk-2.0 
-I/usr/lib64/gtk-2.0/include -I/usr/X11R6/include -I/usr/include/atk-1.0 
-I/usr/include/pango-1.0 -I/usr/include/freetype2 
-I/usr/include/freetype2/freetype2 -I/usr/include/freetype2/freetype2/config 
-I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include 
-I/usr/include/python2.3 -c CXX/cxx_extensions.cxx -o 
build/temp.linux-x86_64-2.3/CXX/cxx_extensions.o
./CXX/Extensions.hxx: In constructor 
`Py::PythonExtension<T>::PythonExtension() [with T = 
Py::ExtensionModuleBasePtr]':
CXX/cxx_extensions.cxx:92:   instantiated from here
./CXX/Extensions.hxx:472: warning: right-hand operand of comma has no effect
gcc -pthread -fno-strict-aliasing -DNDEBUG -O2 -pipe -Wall -g -fPIC 
-I/usr/local/include -I/usr/include -Isrc -Iagg22/include -I. 
-I/usr/local/include -I/usr/include -I/usr/local/include/freetype2 
-I/usr/include/freetype2 -Isrc/freetype2 -Iagg22/include/freetype2 
-I./freetype2 -I/usr/local/include/freetype2 -I/usr/include/freetype2 
-I/usr/local/include -I/usr/include -I/usr/include/pygtk-2.0 
-I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/gtk-2.0 
-I/usr/lib64/gtk-2.0/include -I/usr/X11R6/include -I/usr/include/atk-1.0 
-I/usr/include/pango-1.0 -I/usr/include/freetype2 
-I/usr/include/freetype2/freetype2 -I/usr/include/freetype2/freetype2/config 
-I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include 
-I/usr/include/python2.3 -c src/mplutils.cpp -o 
build/temp.linux-x86_64-2.3/src/mplutils.o
gcc -pthread -fno-strict-aliasing -DNDEBUG -O2 -pipe -Wall -g -fPIC 
-I/usr/local/include -I/usr/include -Isrc -Iagg22/include -I. 
-I/usr/local/include -I/usr/include -I/usr/local/include/freetype2 
-I/usr/include/freetype2 -Isrc/freetype2 -Iagg22/include/freetype2 
-I./freetype2 -I/usr/local/include/freetype2 -I/usr/include/freetype2 
-I/usr/local/include -I/usr/include -I/usr/include/pygtk-2.0 
-I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/gtk-2.0 
-I/usr/lib64/gtk-2.0/include -I/usr/X11R6/include -I/usr/include/atk-1.0 
-I/usr/include/pango-1.0 -I/usr/include/freetype2 
-I/usr/include/freetype2/freetype2 -I/usr/include/freetype2/freetype2/config 
-I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include 
-I/usr/include/python2.3 -c CXX/cxxsupport.cxx -o 
build/temp.linux-x86_64-2.3/CXX/cxxsupport.o
gcc -pthread -fno-strict-aliasing -DNDEBUG -O2 -pipe -Wall -g -fPIC 
-I/usr/local/include -I/usr/include -Isrc -Iagg22/include -I. 
-I/usr/local/include -I/usr/include -I/usr/local/include/freetype2 
-I/usr/include/freetype2 -Isrc/freetype2 -Iagg22/include/freetype2 
-I./freetype2 -I/usr/local/include/freetype2 -I/usr/include/freetype2 
-I/usr/local/include -I/usr/include -I/usr/include/pygtk-2.0 
-I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/gtk-2.0 
-I/usr/lib64/gtk-2.0/include -I/usr/X11R6/include -I/usr/include/atk-1.0 
-I/usr/include/pango-1.0 -I/usr/include/freetype2 
-I/usr/include/freetype2/freetype2 -I/usr/include/freetype2/freetype2/config 
-I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include 
-I/usr/include/python2.3 -c src/_gtkagg.cpp -o 
build/temp.linux-x86_64-2.3/src/_gtkagg.o
In file included from /usr/include/python2.3/Python.h:8,
                 from /usr/include/pygtk-2.0/pygobject.h:5,
                 from src/_gtkagg.cpp:8:
/usr/include/python2.3/pyconfig.h:850:1: warning: "_POSIX_C_SOURCE" redefined
In file included from /usr/include/string.h:26,
                 from /usr/lib64/gcc/x86_64-mandrake-linux-gnu/3.4.1/../../../../include/c++/3.4.1/cstring:51,
                 from src/_gtkagg.cpp:1:
/usr/include/features.h:132:1: warning: this is the location of the previous 
definition
In file included from src/_gtkagg.cpp:8:
/usr/include/pygtk-2.0/pygobject.h:124: error: expected `,' or `...' before 
"typename"
/usr/include/pygtk-2.0/pygobject.h:131: error: expected `,' or `...' before 
"typename"
In file included from agg22/include/agg_vertex_sequence.h:23,
                 from agg22/include/agg_vcgen_contour.h:20,
                 from agg22/include/agg_conv_contour.h:23,
                 from src/_backend_agg.h:13,
                 from src/_gtkagg.cpp:11:
agg22/include/agg_array.h: In member function `agg::int8u* 
agg::pod_allocator::allocate(unsigned int, unsigned int)':
agg22/include/agg_array.h:581: warning: cast from pointer to integer of 
different size
error: command 'gcc' failed with exit status 1



I wonder if it can be due to x86_64 architecture or a wrong devel version in 
the required libs.
It would be a great help if someone could give me a few advices or an idea 
about how to yank out this nasty mess.

I thank you in advance for your contribution and feel sorry for my bad 
english,


Laurent


PS: I successfuly built gtk, pygtk, numarray, OpenGL for my python 2.3