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Goyo wrote:
> El lun, 13-10-2008 a las 00:41 +0200, Goyo escribió:
> 
>> But I don't know how to set the dpi value this way. I tried to use the
>> OO API but no success.
> 
> Well yes...
> 
> import matplotlib
> matplotlib.use('GTKAgg')
> from matplotlib import pyplot
> fig = pyplot.figure(dpi=100)
> ax = fig.add_subplot('111')
> ax.plot([1, 2, 3], [1, 2, 3])
> fig.savefig('test.jpg')
> 
> But changing the dpi value has no effect so maybe I'm missing something.

The figure dpi is irrelevant when saving the figure; only the dpi 
specified in the savefig command matters for that.  This is inherently 
confusing.  I'm thinking about a solution, but haven't tried it yet.

Eric

Goyo wrote:
> Hi all,
> 
> I'm plotting time series and using a custom format for x tick labels
> because I want to see both date and time. But calling xlim makes the
> default format return -- only dates or only times, it depends on the
> displayed interval.
> 
> I can get my preferred format back by calling set_major_formatter again,
> but this is inconvenient for interactive use.
> 
> I wonder if there is a better way for changing x limits while keeping
> tick labels format unchanged.
> 
> I'm using matplotlib 0.98.3
> 
> Thanks
> 
> Goyo
> 
> 
> Sample code -- you need a combination of python shell and matplotlib GUI
> which allows for interactive use in order to get this working as
> expected:
> 
> ----------------------------------------
> 
> from matplotlib import pyplot
> from matplotlib import dates
> from datetime import datetime, timedelta
> from numpy import random
> 
> pyplot.ion()
> 
> # create data
> dstart = datetime(2008, 1, 1, 0, 0)
> dend = datetime(2008, 1, 5, 23, 50)
> delta = timedelta(minutes=10)
> x = dates.drange(dstart, dend, delta)
> y = random.random_sample(len(x))
> 
> # plot data
> pyplot.plot(x, y)
> 
> # format x tick labels
> axis = pyplot.gca()
> fig = pyplot.gcf()
> axis.xaxis.set_major_formatter(dates.DateFormatter('%Y-%b-%d %H:%M'))
> fig.autofmt_xdate()
> 
> # draw the figure
> pyplot.draw()
> 
> --------------------------------------
> 
> Look at the tick labels, they show both date and time even if you zoom
> and pan using the GUI.
> 
> Now if I want to look at the second day:
> 
> dstart = datetime(2008, 1, 1, 0, 0)
> dend = datetime(2008, 1, 1, 23, 50)
> pyplot.xlim(dstart, dend)
> 
> And the format has changed.

I don't see this problem using ipython -pylab with mpl from svn on 
linux, gtkagg backend.  What version, backend, and platform are you using?

Eric

El lun, 13-10-2008 a las 00:41 +0200, Goyo escribió:

> But I don't know how to set the dpi value this way. I tried to use the
> OO API but no success.

Well yes...

import matplotlib
matplotlib.use('GTKAgg')
from matplotlib import pyplot
fig = pyplot.figure(dpi=100)
ax = fig.add_subplot('111')
ax.plot([1, 2, 3], [1, 2, 3])
fig.savefig('test.jpg')

But changing the dpi value has no effect so maybe I'm missing something.

Goyo

Goyo wrote:
> I can't make much sense of this. You don't plot anything and don't use
> canvas.
> 
> This code works:
> 
> import matplotlib
> matplotlib.use('GTKAgg')
> from matplotlib import pyplot
> pyplot.plot([0, 1, 2, 3], [0, 1, 2, 3])
> fig = pyplot.gcf()
> fig.savefig('test.jpg')

fig.savefig('test.jpg', dpi=150) # or whatever dpi you want

If you are only using savefig, not plotting to the screen, then you 
might as well use the agg backend, not the gtkagg.

Eric

> 
> But I don't know how to set the dpi value this way. I tried to use the
> OO API but no success.
> 
> Goyo
> 
> El dom, 12-10-2008 a las 23:45 +0200, Jesper Larsen escribió:
>> Hi matplotlib-users,
>>
>> I decided to try to make some plots that I have previously made in png
>> format using the Agg backend in jpeg format using the GTKAgg backend
>> (which I guess is the one I should use for this). Unfortunately my
>> script exits with an error. I have therefore created a simple test
>> script (test.py) that illustrates the problem (at least on my
>> computer):
>>
>> import matplotlib
>> from matplotlib.backends.backend_gtkagg import FigureCanvasGTKAgg as
>> FigureCanvas
>>
>> fig = matplotlib.figure.Figure(dpi=100)
>> canvas = FigureCanvas(fig)
>> fig.savefig('test.jpg')
>>
>> When I run it I get:
>>
>> $ python test.py
>> /usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py:357:
>> GtkWarning: gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED
>> (widget) || GTK_IS_INVISIBLE (widget)' failed
>>   gtk.DrawingArea.realize(self)
>> /usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py:360:
>> GtkWarning: gdk_pixmap_new: assertion `(drawable != NULL) || (depth !=
>> -1)' failed
>>   pixmap = gdk.Pixmap (self.window, width, height)
>> Traceback (most recent call last):
>>   File "test.py", line 6, in <module>
>>     fig.savefig('test.jpg')
>>   File "/usr/lib/python2.5/site-packages/matplotlib/figure.py", line
>> 964, in savefig
>>     self.canvas.print_figure(*args, **kwargs)
>>   File "/usr/lib/python2.5/site-packages/matplotlib/backend_bases.py",
>> line 1310, in print_figure
>>     **kwargs)
>>   File "/usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py",
>> line 347, in print_jpeg
>>     return self._print_image(filename, 'jpeg')
>>   File "/usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py",
>> line 360, in _print_image
>>     pixmap = gdk.Pixmap (self.window, width, height)
>> RuntimeError: could not create GdkPixmap object
>>
>> I am using matplotlib 0.98.3, pygtk 2.14.0. My system is a Linux Ubuntu:
>>
>> $ uname -a
>> Linux <blanket out> #1 SMP Wed Aug 20 18:39:13 UTC 2008 i686 GNU/Linux
>>
>> Does anyone know what is wrong?
>>
>> Best regards,
>> Jesper

I can't make much sense of this. You don't plot anything and don't use
canvas.

This code works:

import matplotlib
matplotlib.use('GTKAgg')
from matplotlib import pyplot
pyplot.plot([0, 1, 2, 3], [0, 1, 2, 3])
fig = pyplot.gcf()
fig.savefig('test.jpg')

But I don't know how to set the dpi value this way. I tried to use the
OO API but no success.

Goyo

El dom, 12-10-2008 a las 23:45 +0200, Jesper Larsen escribió:
> Hi matplotlib-users,
> 
> I decided to try to make some plots that I have previously made in png
> format using the Agg backend in jpeg format using the GTKAgg backend
> (which I guess is the one I should use for this). Unfortunately my
> script exits with an error. I have therefore created a simple test
> script (test.py) that illustrates the problem (at least on my
> computer):
> 
> import matplotlib
> from matplotlib.backends.backend_gtkagg import FigureCanvasGTKAgg as
> FigureCanvas
> 
> fig = matplotlib.figure.Figure(dpi=100)
> canvas = FigureCanvas(fig)
> fig.savefig('test.jpg')
> 
> When I run it I get:
> 
> $ python test.py
> /usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py:357:
> GtkWarning: gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED
> (widget) || GTK_IS_INVISIBLE (widget)' failed
>   gtk.DrawingArea.realize(self)
> /usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py:360:
> GtkWarning: gdk_pixmap_new: assertion `(drawable != NULL) || (depth !=
> -1)' failed
>   pixmap = gdk.Pixmap (self.window, width, height)
> Traceback (most recent call last):
>   File "test.py", line 6, in <module>
>     fig.savefig('test.jpg')
>   File "/usr/lib/python2.5/site-packages/matplotlib/figure.py", line
> 964, in savefig
>     self.canvas.print_figure(*args, **kwargs)
>   File "/usr/lib/python2.5/site-packages/matplotlib/backend_bases.py",
> line 1310, in print_figure
>     **kwargs)
>   File "/usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py",
> line 347, in print_jpeg
>     return self._print_image(filename, 'jpeg')
>   File "/usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py",
> line 360, in _print_image
>     pixmap = gdk.Pixmap (self.window, width, height)
> RuntimeError: could not create GdkPixmap object
> 
> I am using matplotlib 0.98.3, pygtk 2.14.0. My system is a Linux Ubuntu:
> 
> $ uname -a
> Linux <blanket out> #1 SMP Wed Aug 20 18:39:13 UTC 2008 i686 GNU/Linux
> 
> Does anyone know what is wrong?
> 
> Best regards,
> Jesper
> 
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
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> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
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Hi all,

I'm plotting time series and using a custom format for x tick labels
because I want to see both date and time. But calling xlim makes the
default format return -- only dates or only times, it depends on the
displayed interval.

I can get my preferred format back by calling set_major_formatter again,
but this is inconvenient for interactive use.

I wonder if there is a better way for changing x limits while keeping
tick labels format unchanged.

I'm using matplotlib 0.98.3

Thanks

Goyo


Sample code -- you need a combination of python shell and matplotlib GUI
which allows for interactive use in order to get this working as
expected:

----------------------------------------

from matplotlib import pyplot
from matplotlib import dates
from datetime import datetime, timedelta
from numpy import random

pyplot.ion()

# create data
dstart = datetime(2008, 1, 1, 0, 0)
dend = datetime(2008, 1, 5, 23, 50)
delta = timedelta(minutes=10)
x = dates.drange(dstart, dend, delta)
y = random.random_sample(len(x))

# plot data
pyplot.plot(x, y)

# format x tick labels
axis = pyplot.gca()
fig = pyplot.gcf()
axis.xaxis.set_major_formatter(dates.DateFormatter('%Y-%b-%d %H:%M'))
fig.autofmt_xdate()

# draw the figure
pyplot.draw()

--------------------------------------

Look at the tick labels, they show both date and time even if you zoom
and pan using the GUI.

Now if I want to look at the second day:

dstart = datetime(2008, 1, 1, 0, 0)
dend = datetime(2008, 1, 1, 23, 50)
pyplot.xlim(dstart, dend)

And the format has changed.

never mind. Got it working. One annoying thing, though, when the line 
reaches the edge of the figure, a line is drawn horizontally to the 
other side. This doesn't happen when I display all of the points at once.

Mathew

Mathew Yeates wrote:
> something isn't working
> In my main routine I have
> xpt,ypt= m(lons[0:500],lats[0:500])
> outlines=m.plot(xpt,ypt,'r-') #m is my basemap, outlines is a list of 
> size 1. Huh?
>
> then in my update routine I have
> counter=0
> def update():
>     global counter
>     xpt,ypt= 
> m(lons[counter*500:(counter+1)*500],lats[counter*500:(counter+1)*500])
>     counter += 1
>     outlines[0].set_data(xpt,ypt)
>     canvas.draw_idle()
>     return True
>
> but this produces strange results. After a few iterations the line 
> disappears  completely. Is it wrong to use lists when I get xpt and ypt?
>
> Mathew
>
>
>
>
>
> Jeff Whitaker wrote:
>   
>> Mathew Yeates wrote:
>>     
>>> Hi
>>>
>>> I see the example of updating a plot in 
>>> examples/animation/gtk_timeout.py where the 2 lines
>>> ----
>>> line.set_ydata(np.random.rand(10))
>>> fig.canvas.draw_idle()
>>> ----
>>>
>>>
>>> What is the equivalent when I want to update a Basemap with new 
>>> latitudes and longitudes  and I have done
>>> m=Basemap(......)
>>> m.plot(longitude_list,latitude_list)
>>>
>>> Thanks
>>> Mathew
>>>   
>>>       
>> Mathew:  The Basemap plot method returns a list of matplotlib Line2d 
>> objects which you can use just as in the example.
>>
>> -Jeff
>>
>>     
>
>
>
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
> Build the coolest Linux based applications with Moblin SDK & win great prizes
> Grand prize is a trip for two to an Open Source event anywhere in the world
> http://moblin-contest.org/redirect.php?banner_id=100&url=/
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
>   

Mathew Yeates wrote:
> something isn't working
> In my main routine I have
> xpt,ypt= m(lons[0:500],lats[0:500])
> outlines=m.plot(xpt,ypt,'r-') #m is my basemap, outlines is a list of 
> size 1. Huh?

Mathew:  It's one line, so the list has one Line2D object.
>
> then in my update routine I have
> counter=0
> def update():
>    global counter
>    xpt,ypt= 
> m(lons[counter*500:(counter+1)*500],lats[counter*500:(counter+1)*500])
>    counter += 1
>    outlines[0].set_data(xpt,ypt)
>    canvas.draw_idle()
>    return True
>
> but this produces strange results. After a few iterations the line 
> disappears  completely. Is it wrong to use lists when I get xpt and ypt?
>
> Mathew
Don't really understand what you're trying to do here, so I can't comment.

-Jeff
>
>
>
>
>
> Jeff Whitaker wrote:
>> Mathew Yeates wrote:
>>> Hi
>>>
>>> I see the example of updating a plot in 
>>> examples/animation/gtk_timeout.py where the 2 lines
>>> ----
>>> line.set_ydata(np.random.rand(10))
>>> fig.canvas.draw_idle()
>>> ----
>>>
>>>
>>> What is the equivalent when I want to update a Basemap with new 
>>> latitudes and longitudes  and I have done
>>> m=Basemap(......)
>>> m.plot(longitude_list,latitude_list)
>>>
>>> Thanks
>>> Mathew
>>>   
>>
>> Mathew:  The Basemap plot method returns a list of matplotlib Line2d 
>> objects which you can use just as in the example.
>>
>> -Jeff
>>
>
>


-- 
Jeffrey S. Whitaker         Phone : (303)497-6313
NOAA/OAR/CDC  R/PSD1        FAX   : (303)497-6449
325 Broadway                Boulder, CO, USA 80305-3328

Hi matplotlib-users,

I decided to try to make some plots that I have previously made in png
format using the Agg backend in jpeg format using the GTKAgg backend
(which I guess is the one I should use for this). Unfortunately my
script exits with an error. I have therefore created a simple test
script (test.py) that illustrates the problem (at least on my
computer):

import matplotlib
from matplotlib.backends.backend_gtkagg import FigureCanvasGTKAgg as
FigureCanvas

fig = matplotlib.figure.Figure(dpi=100)
canvas = FigureCanvas(fig)
fig.savefig('test.jpg')

When I run it I get:

$ python test.py
/usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py:357:
GtkWarning: gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED
(widget) || GTK_IS_INVISIBLE (widget)' failed
  gtk.DrawingArea.realize(self)
/usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py:360:
GtkWarning: gdk_pixmap_new: assertion `(drawable != NULL) || (depth !=
-1)' failed
  pixmap = gdk.Pixmap (self.window, width, height)
Traceback (most recent call last):
  File "test.py", line 6, in <module>
    fig.savefig('test.jpg')
  File "/usr/lib/python2.5/site-packages/matplotlib/figure.py", line
964, in savefig
    self.canvas.print_figure(*args, **kwargs)
  File "/usr/lib/python2.5/site-packages/matplotlib/backend_bases.py",
line 1310, in print_figure
    **kwargs)
  File "/usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py",
line 347, in print_jpeg
    return self._print_image(filename, 'jpeg')
  File "/usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py",
line 360, in _print_image
    pixmap = gdk.Pixmap (self.window, width, height)
RuntimeError: could not create GdkPixmap object

I am using matplotlib 0.98.3, pygtk 2.14.0. My system is a Linux Ubuntu:

$ uname -a
Linux <blanket out> #1 SMP Wed Aug 20 18:39:13 UTC 2008 i686 GNU/Linux

Does anyone know what is wrong?

Best regards,
Jesper

something isn't working
In my main routine I have
xpt,ypt= m(lons[0:500],lats[0:500])
outlines=m.plot(xpt,ypt,'r-') #m is my basemap, outlines is a list of 
size 1. Huh?

then in my update routine I have
counter=0
def update():
    global counter
    xpt,ypt= 
m(lons[counter*500:(counter+1)*500],lats[counter*500:(counter+1)*500])
    counter += 1
    outlines[0].set_data(xpt,ypt)
    canvas.draw_idle()
    return True

but this produces strange results. After a few iterations the line 
disappears  completely. Is it wrong to use lists when I get xpt and ypt?

Mathew





Jeff Whitaker wrote:
> Mathew Yeates wrote:
>> Hi
>>
>> I see the example of updating a plot in 
>> examples/animation/gtk_timeout.py where the 2 lines
>> ----
>> line.set_ydata(np.random.rand(10))
>> fig.canvas.draw_idle()
>> ----
>>
>>
>> What is the equivalent when I want to update a Basemap with new 
>> latitudes and longitudes  and I have done
>> m=Basemap(......)
>> m.plot(longitude_list,latitude_list)
>>
>> Thanks
>> Mathew
>>   
>
> Mathew:  The Basemap plot method returns a list of matplotlib Line2d 
> objects which you can use just as in the example.
>
> -Jeff
>

Mathew Yeates wrote:
> Hi
>
> I see the example of updating a plot in 
> examples/animation/gtk_timeout.py where the 2 lines
> ----
> line.set_ydata(np.random.rand(10))
> fig.canvas.draw_idle()
> ----
>
>
> What is the equivalent when I want to update a Basemap with new 
> latitudes and longitudes  and I have done
> m=Basemap(......)
> m.plot(longitude_list,latitude_list)
>
> Thanks
> Mathew
>   

Mathew:  The Basemap plot method returns a list of matplotlib Line2d 
objects which you can use just as in the example.

-Jeff

-- 
Jeffrey S. Whitaker         Phone : (303)497-6313
NOAA/OAR/CDC  R/PSD1        FAX   : (303)497-6449
325 Broadway                Boulder, CO, USA 80305-3328

Hi

I see the example of updating a plot in 
examples/animation/gtk_timeout.py where the 2 lines
----
line.set_ydata(np.random.rand(10))
fig.canvas.draw_idle()
----


What is the equivalent when I want to update a Basemap with new 
latitudes and longitudes  and I have done
m=Basemap(......)
m.plot(longitude_list,latitude_list)

Thanks
Mathew

I'm having an unusually hard time with plotting some data on a date axis. 
All I want to do is plot several data series over a specific 8 week period. It works fine when I plot all the data (that is not specifying a date range) but
when I try to use the axis command to put in my limits it puts the scales up nicely but no data points appear and moreover then I reload and run it again it
goes into an infinite loop. I've tried it with Matplotlib 0.90.1 and 0.98.1 with the same results.

The plot() method below:


class Plotter:
    """Generate plots of disk trend data
    """
    Marker = ['s','o','^','d','v','p','x','+','h','<','>','1']
    Color = ['black','red','blue','green','aqua','fuchsia',
             'navy','purple','olive','maroon','gray','teal']

    def __init__(self, trenddict):
        self.trenddict = trenddict
        self.today = datetime.date.today()
        self.dates = trenddict.keys() #keys are datetime objects
        self.dates.sort() #sorted list of datetime objects

    def extract(self, dirlist):
        x = []
        ys = {}
        for date in self.dates:
            x.append(date2num(date))
            for dirname in dirlist:
                value = self.trenddict[date][dirname]
                try:
                    ys[dirname].append(value)
                except KeyError:
                    ys[dirname] = [value]
        return x, ys
        
    def plot(self, dirlist, title, scalemax, filename):
        fig = figure(num=1, figsize=(8,10), frameon=False)
        ax = fig.add_subplot(111)
        ax.set_title(title)
        ax.xaxis.set_major_locator(WeekdayLocator(MONDAY))
        ax.xaxis.set_minor_locator(MultipleLocator(1))
        ax.yaxis.set_major_locator(MultipleLocator(10))

        ax.set_ylabel("GBytes")
        ax.grid(True)

        start = date2num(self.today - datetime.timedelta(49))
        end  = date2num(self.today + datetime.timedelta(7))
        #fig.autofmt_xdate()
        ax.axis([start, end, 0, scalemax])

        x, ys = self.extract(dirlist)

        for i, directory in enumerate(dirlist):
            plot_date(x, ys[directory],
                      linestyle='-',
                      marker=self.Marker[i],
                      color=self.Color[i],
                      label=directory)

        tl = ax.get_xticklabels()
        setp(tl, 'rotation', 45, fontsize=10)
        legend(loc='lower left', prop=FontProperties(size="smaller"))
        
        savefig(filename)
        show()
        close()
        

Ian Curington wrote:
> Does anyone have extensions or hints on how to create high quality 
> vector contour plots on unstructured triangle meshes, with values at 
> nodes? I can convert to structured with griddata, but I much prefer to 
> get a direct contour from the original triangles. Thanks! 
Ian:  Matplotlib's contour cannot do this (although I believe the 
underlying c code does have this capability).  I think it would be a 
useful addition.  For right now, however, your workaround is the best 
solution. 

PyNGL (http://www.pyngl.ucar.edu/Graphics/contour_grids.shtml) can 
contour triangular meshes, if you'd like to give that a try.

-Jeff

-- 
Jeffrey S. Whitaker         Phone : (303)497-6313
NOAA/OAR/CDC  R/PSD1        FAX   : (303)497-6449
325 Broadway                Boulder, CO, USA 80305-3328