matplotlib-users Mailing List for matplotlib

Phillip M. Feldman wrote:
> Jeff Whitaker wrote:
>> Dr. Phillip M. Feldman wrote:
>>> The attached program generates a map and then saves it to a file.  I 
>>> have two
>>> problems with the result:
>>>
>>> (1) Note that the screenshot shows a title above the map, while the 
>>> .png
>>> file that was saved by the program does not.
>>>   
>> Philip:
>>
>> mapdemo.jpeg (which was presumably created from the png saved by your 
>> program) is totally empty.
>>> (2) I would like to be able to label the lines of latitude and 
>>> longitude,
>>> but have not been able to figure out how to do this.
>>>   
>>
>> use the label keyword to drawmeridians and drawparallels.
>>
>> -Jeff
>>
> Hello Jeff,
>
> I had tried that, but thought that it wasn't working because I wasn't 
> seeing anything on the screen.  I now think that the label parameter 
> must be working, because the lines of latitude and longitude are 
> labeled in the version of the map that is saved by the program, and 
> that I'm not seeing them on the screen because I have black text on a 
> black background.  Is there a way to control the color of the text 
> labels?  Note also that the plot title appears on the screen shot 
> jpeg, but not in the version saved by the program.  Any advice will be 
> appreciated.
>
> Philllip

Philip:  To change the color of the lat/lon lines, use the color keyword 
in drawparallels and drawmeridians (i.e. color="red").  To change the 
font color for the labels, use fontdict=dict(color='red').  The plot 
title color can be changed in the same way.
-Jeff
>
> ------------------------------------------------------------------------
>
> ------------------------------------------------------------------------
>


-- 
Jeffrey S. Whitaker         Phone  : (303)497-6313
Meteorologist               FAX    : (303)497-6449
NOAA/OAR/PSD  R/PSD1        Email  : Jef...@no...
325 Broadway                Office : Skaggs Research Cntr 1D-113
Boulder, CO, USA 80303-3328 Web    : http://tinyurl.com/5telg

Jeff Whitaker wrote:
> Dr. Phillip M. Feldman wrote:
>> The attached program generates a map and then saves it to a file.  I 
>> have two
>> problems with the result:
>>
>> (1) Note that the screenshot shows a title above the map, while the .png
>> file that was saved by the program does not.
>>   
> Philip:
>
> mapdemo.jpeg (which was presumably created from the png saved by your 
> program) is totally empty.
>> (2) I would like to be able to label the lines of latitude and 
>> longitude,
>> but have not been able to figure out how to do this.
>>   
>
> use the label keyword to drawmeridians and drawparallels.
>
> -Jeff
>
Hello Jeff,

I had tried that, but thought that it wasn't working because I wasn't 
seeing anything on the screen.  I now think that the label parameter 
must be working, because the lines of latitude and longitude are labeled 
in the version of the map that is saved by the program, and that I'm not 
seeing them on the screen because I have black text on a black 
background.  Is there a way to control the color of the text labels?  
Note also that the plot title appears on the screen shot jpeg, but not 
in the version saved by the program.  Any advice will be appreciated.

Philllip

Hello,

I'm trying to make a log plot using set_xscale and set_yscale. The default LogFormatter however shows 10^-1, 10^0, and 10^1 rather than 0.1, 1, and 10 (other plotting packages I've used usually automatically substitute these three common labels). Is there a way that the LogFormatter could have an extra option for basically enabling this (or even better, that this be made the default, with an option to disable - I don't see most people wanting 1 shown as 10^0)?

Cheers,

Thomas

Dr. Phillip M. Feldman wrote:
> The attached program generates a map and then saves it to a file.  I have two
> problems with the result:
>
> (1) Note that the screenshot shows a title above the map, while the .png
> file that was saved by the program does not.
>   
Philip:

mapdemo.jpeg (which was presumably created from the png saved by your 
program) is totally empty. 
> (2) I would like to be able to label the lines of latitude and longitude,
> but have not been able to figure out how to do this.
>   

use the label keyword to drawmeridians and drawparallels.

-Jeff
> Thanks!
>
> Phillip
>
> http://old.nabble.com/file/p27313185/mapdemo.py mapdemo.py 
> http://old.nabble.com/file/p27313185/mapdemo%2Bscreenshot.jpeg 
> http://old.nabble.com/file/p27313185/mapdemo.jpeg 
>
>   


-- 
Jeffrey S. Whitaker         Phone  : (303)497-6313
Meteorologist               FAX    : (303)497-6449
NOAA/OAR/PSD  R/PSD1        Email  : Jef...@no...
325 Broadway                Office : Skaggs Research Cntr 1D-113
Boulder, CO, USA 80303-3328 Web    : http://tinyurl.com/5telg

The attached program generates a map and then saves it to a file.  I have two
problems with the result:

(1) Note that the screenshot shows a title above the map, while the .png
file that was saved by the program does not.

(2) I would like to be able to label the lines of latitude and longitude,
but have not been able to figure out how to do this.

Thanks!

Phillip

http://old.nabble.com/file/p27313185/mapdemo.py mapdemo.py 
http://old.nabble.com/file/p27313185/mapdemo%2Bscreenshot.jpeg 
http://old.nabble.com/file/p27313185/mapdemo.jpeg 

-- 
View this message in context: http://old.nabble.com/two-issues-with-labels-on-maps-tp27313185p27313185.html
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Gökhan Sever wrote:
> Hello,
>
> I have thought of this might interesting to share. Register at
> www.sagenb.org or try on your local Sage-notebook and using the following
> code:
>   
>

A related example that lets you get the actual matplotlib figure from a 
Sage graphic and play with it is here:

http://sagenb.org/home/pub/1413/

The thing we'd like to do now is be able to wrap matplotlib axes with 
Sage Graphics objects (so someone can construct a matplotlib object and 
then wrap it in a Sage Graphics instance to then do further stuff with 
it in Sage).  However, I think we need to resolve the issues involving 
taking the axes from one figure and adding them to another figure; these 
issues were brought up on the mailing list a while ago.

Thanks,

Jason

--
Jason Grout
jas...@dr...

Yes.  Unicode strings can be used for text.  See this example:

http://matplotlib.sourceforge.net/examples/pylab_examples/unicode_demo.html

(There are some caveats about using characters outside of the BMP, but 
that doesn't affect most people.)

Mike

Filipe Pires Alvarenga Fernandes wrote:
> Does matplotlib support accented characters without the TeX mathtext?
>
> Thanks.
>
> *****************************************************
> Filipe Pires Alvarenga Fernandes
>
> University of Massachusetts Dartmouth
> 200 Mill Road - Fairhaven, MA
> Tel: (508) 910-6381
> Email: fal...@um... 
> <mailto:fal...@um...>
>          oc...@ya... <mailto:oc...@ya...>
>          oc...@gm... <mailto:oc...@gm...>
>
> http://ocefpaf.tiddlyspot.com/
> *****************************************************
> ------------------------------------------------------------------------
>
> ------------------------------------------------------------------------------
> The Planet: dedicated and managed hosting, cloud storage, colocation
> Stay online with enterprise data centers and the best network in the business
> Choose flexible plans and management services without long-term contracts
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> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>   

-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

Does matplotlib support accented characters without the TeX mathtext?

Thanks.

*****************************************************
Filipe Pires Alvarenga Fernandes

University of Massachusetts Dartmouth
200 Mill Road - Fairhaven, MA
Tel: (508) 910-6381
Email: fal...@um...
         oc...@ya...
         oc...@gm...

http://ocefpaf.tiddlyspot.com/
*****************************************************

Constrain pan/zoom to x axis hold *x* Constrain pan/zoom to y axis hold *y*
I don't have these in my backend_bases.py file. Are these working on your
system?

On Mon, Jan 25, 2010 at 12:58 PM, Gökhan Sever <gok...@gm...>wrote:

> Hello,
>
> I could these keys into rcsetup.py file as well as matplotlibrc.template
> and update backend_bases.py accordingly. And add some documentation
> reflecting
> the changes made.
>
> # Event keys to interact with figures/plots via keyboard
>
> fullscreen : 'f'
> home : 'h'
> reset : 'r'
> back : 'c'
> forward : 'v'
> pan : 'p'
> zoom : 'o'
> save : 's'
> grid : 'g'
> yscale : 'l'
> xscale : 'k'
>
>
> *Notes:*
>
> Matthias, leaving values as empty will remove the key short-cut.
>
> Don't understand exactly what 'a' does?
>
> f doesn't toggle full-screen --using qt4agg backend.
>
> There are a couple function duplicates. (eg. back with 'c' and left and
> backspace keys. How can represent them? Create a list inside the
> dictionary?
> back = ['c', 'left', 'backspace']
>
> 'o' seems like unnecessary. Since you have to select an area using mouse.
>
> 's' doesn't behave correctly here. Shouldn't it bring the save dialog?
> Instead I am getting:
> TypeError: save_figure() takes exactly 1 argument (2 given)
>
>
>
> On Mon, Jan 25, 2010 at 8:32 AM, Matthias Michler <Mat...@gm...
> > wrote:
>
>> Hi Gökhan,
>>
>> I just wanted to discuss the key, because I think this patch should be
>> part of
>> matplotlib and not only of individual users. I think it is worth be be
>> added
>> to the mpl-tracker at http://sourceforge.net/tracker/?group_id=80706 or
>> maybe
>> one of the developers has the time to commit this small change?
>>
>> I think your idea about key-mappings in the matplotlib-rc is a good option
>> to
>> customize keyboard short cuts and even remove short-cuts which aren't of
>> intrest for the individual user. Furthermore the latter yields space for
>> keyboard shortcuts, which are used in one's own program.
>>
>> Kind regards,
>> Matthias
>>
>> On Friday 22 January 2010 16:57:22 Gökhan Sever wrote:
>> > It is very simple to change key-assignment. Take a look at the
>> > backend_bases.py code (search for event.key instances) :
>> >
>> >         elif event.key == 'L':
>> >
>> > I was thinking to move y-scaling to "y" and x-scaling to "x" but x and y
>> > are assigned to something else (
>> > http://matplotlib.sourceforge.net/users/navigation_toolbar.html)
>> >
>> > For me toggling "k" is simpler for me than doing Shift-L.
>> >
>> > Maybe these options could be provided in the matplotlibrc file. Users
>> can
>> > make their key mapping based on their choice. That requires some more
>> > coding
>> >
>> > :)
>> >
>> > On Fri, Jan 22, 2010 at 1:59 AM, Matthias Michler
>> >
>> > <Mat...@gm...>wrote:
>> > > Hi Gökhan, Hi list members,
>> > >
>> > > This is really a missing feature in matplotlib in my opinion and it's
>> > > great that you took the time to make an suggestion, but I would prefer
>> > > capital "L"
>> > > for the xaxis-scaling like gnuplot although I'm not sure this is
>> > > possible.
>> > >
>> > > What do you and other list members think about that?
>> > >
>> > > Kind regards,
>> > > Matthias
>> > >
>> > > On Thursday 21 January 2010 19:45:37 Gökhan Sever wrote:
>> > > > Hello,
>> > > >
>> > > > "l" key does the log - linear scaling for y-axis. I have made a
>> minor
>> > > > change to use "k" for x-axis scaling.
>> > > >
>> > > > Patch added. Feel free to add if you find it useful.
>>
>>
>>
>> ------------------------------------------------------------------------------
>> Throughout its 18-year history, RSA Conference consistently attracts the
>> world's best and brightest in the field, creating opportunities for
>> Conference
>> attendees to learn about information security's most important issues
>> through
>> interactions with peers, luminaries and emerging and established
>> companies.
>> http://p.sf.net/sfu/rsaconf-dev2dev
>> _______________________________________________
>> Matplotlib-users mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>>
>
>
>
> --
> Gökhan
>



-- 
Gökhan

Hello,

I could these keys into rcsetup.py file as well as matplotlibrc.template
and update backend_bases.py accordingly. And add some documentation
reflecting
the changes made.

# Event keys to interact with figures/plots via keyboard

fullscreen : 'f'
home : 'h'
reset : 'r'
back : 'c'
forward : 'v'
pan : 'p'
zoom : 'o'
save : 's'
grid : 'g'
yscale : 'l'
xscale : 'k'


*Notes:*

Matthias, leaving values as empty will remove the key short-cut.

Don't understand exactly what 'a' does?

f doesn't toggle full-screen --using qt4agg backend.

There are a couple function duplicates. (eg. back with 'c' and left and
backspace keys. How can represent them? Create a list inside the dictionary?
back = ['c', 'left', 'backspace']

'o' seems like unnecessary. Since you have to select an area using mouse.

's' doesn't behave correctly here. Shouldn't it bring the save dialog?
Instead I am getting:
TypeError: save_figure() takes exactly 1 argument (2 given)


On Mon, Jan 25, 2010 at 8:32 AM, Matthias Michler
<Mat...@gm...>wrote:

> Hi Gökhan,
>
> I just wanted to discuss the key, because I think this patch should be part
> of
> matplotlib and not only of individual users. I think it is worth be be
> added
> to the mpl-tracker at http://sourceforge.net/tracker/?group_id=80706 or
> maybe
> one of the developers has the time to commit this small change?
>
> I think your idea about key-mappings in the matplotlib-rc is a good option
> to
> customize keyboard short cuts and even remove short-cuts which aren't of
> intrest for the individual user. Furthermore the latter yields space for
> keyboard shortcuts, which are used in one's own program.
>
> Kind regards,
> Matthias
>
> On Friday 22 January 2010 16:57:22 Gökhan Sever wrote:
> > It is very simple to change key-assignment. Take a look at the
> > backend_bases.py code (search for event.key instances) :
> >
> >         elif event.key == 'L':
> >
> > I was thinking to move y-scaling to "y" and x-scaling to "x" but x and y
> > are assigned to something else (
> > http://matplotlib.sourceforge.net/users/navigation_toolbar.html)
> >
> > For me toggling "k" is simpler for me than doing Shift-L.
> >
> > Maybe these options could be provided in the matplotlibrc file. Users can
> > make their key mapping based on their choice. That requires some more
> > coding
> >
> > :)
> >
> > On Fri, Jan 22, 2010 at 1:59 AM, Matthias Michler
> >
> > <Mat...@gm...>wrote:
> > > Hi Gökhan, Hi list members,
> > >
> > > This is really a missing feature in matplotlib in my opinion and it's
> > > great that you took the time to make an suggestion, but I would prefer
> > > capital "L"
> > > for the xaxis-scaling like gnuplot although I'm not sure this is
> > > possible.
> > >
> > > What do you and other list members think about that?
> > >
> > > Kind regards,
> > > Matthias
> > >
> > > On Thursday 21 January 2010 19:45:37 Gökhan Sever wrote:
> > > > Hello,
> > > >
> > > > "l" key does the log - linear scaling for y-axis. I have made a minor
> > > > change to use "k" for x-axis scaling.
> > > >
> > > > Patch added. Feel free to add if you find it useful.
>
>
>
> ------------------------------------------------------------------------------
> Throughout its 18-year history, RSA Conference consistently attracts the
> world's best and brightest in the field, creating opportunities for
> Conference
> attendees to learn about information security's most important issues
> through
> interactions with peers, luminaries and emerging and established companies.
> http://p.sf.net/sfu/rsaconf-dev2dev
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>



-- 
Gökhan

On Mon, Jan 25, 2010 at 9:14 AM, Dimitri Linten
<dim...@gm...> wrote:
> What is the best way to do this ?

Please explain what you want and what your issue is.
Do not expect us (developers or other users) to study your code. If
possible, post a small stand-alone example that others can simply run.

As far as the watermark is concerned, the easiest way is to use
figimage as John suggested, but apparently this is not what you want.
The svn version of matplotlib has OffsetImage and AnnotationBox, which
could be helpful.

Regards,

-JJ

Dear John,

Thank you for your reply, however am looking for a watermark to be plotted
inside the axis, not behind the axis

Regards,

Dimitri

On Mon, Jan 25, 2010 at 3:58 PM, John Hunter <jd...@gm...> wrote:

> On Mon, Jan 25, 2010 at 8:14 AM, Dimitri Linten
> <dim...@gm...> wrote:
> > Hi Forum,
> > I am using matplotlib in a PyQt4 App.
> > I wanted to add a watermark-type  pictures to the standard white
> background
> > of the canvas.
>
> Does the following help?
>
> http://matplotlib.sourceforge.net/search.html?q=codex+watermark
>

On Mon, Jan 25, 2010 at 8:14 AM, Dimitri Linten
<dim...@gm...> wrote:
> Hi Forum,
> I am using matplotlib in a PyQt4 App.
> I wanted to add a watermark-type  pictures to the standard white background
> of the canvas.

Does the following help?

http://matplotlib.sourceforge.net/search.html?q=codex+watermark

Hi Forum,

I am using matplotlib in a PyQt4 App.

I wanted to add a watermark-type  pictures to the standard white background
of the canvas.

My current version of this is :

    def getwatermark(self):
        factor=1.0  #factor for scaling image
        im1=QtGui.QPixmap(':/watermark.png')
        im=im1.toImage()
        self.watermark_ratio=(im.height()/factor)/(im.width()/factor)
        ival0=[]
        for i in range(im.width()):#range(2): #range(im.width()):
            for j in range(im.height()):#range(3): #range(im.height()):
                if int(im.pixel(i,j))==0:
                      ival0.append(43)
                else:
                     ival0.append(40)
        self.watermark=reshape(ival0,(im.width(),im.height()))

    def placewatermark(self,canvas,axes):

        try:
            if self.version=='1':
                grayfactor=24 #factor for grayscale
                canvassize=canvas.size()
                if canvas.__class__.__name__=='MyPFCanvas':

                     #for PF, the IV canvas is split in two figures...
                    bottom=self.IVTab.IVcanvas.vert[0]._scalable_size
                    spacing=self.IVTab.IVcanvas.vert[1]._scalable_size
                    top=self.IVTab.IVcanvas.vert[2]._scalable_size
                    correctionY=top/(top+spacing+bottom)
                else:
                    correctionY=1

                origaxes=axes.axis()

                xrange=origaxes[1]-origaxes[0]
                yrange=origaxes[3]-origaxes[2]
                xcanvas=canvassize.width()
                ycanvas=canvassize.height()*correctionY

                if (xcanvas/float(ycanvas))>self.watermark_ratio:
                    yfig=yrange
                    centery=origaxes[2]
                    xfig=self.watermark_ratio*yrange

 xfig=(yfig*self.watermark_ratio)*(xrange/yrange)*(ycanvas/float(xcanvas))
                    centerx=origaxes[0]+(xrange-xfig)/2
                else:
                    xfig=xrange
                    centerx=origaxes[0]

 yfig=(xfig/self.watermark_ratio)*(yrange/xrange)/(ycanvas/float(xcanvas))
                    centery=origaxes[2]+(yrange-yfig)/2


 axes.imshow(self.watermark,origin='lower',extent=(centerx,centerx+xfig,centery,centery+yfig),vmin=0,vmax=43,cmap=cm.gray)
 #,extent=(centerx,centerx+xfig,centery,centery+yfig),,

                axes.axis('auto')
                axes.axis(origaxes)

                canvas.draw()
        except:
##            print "no watermark placeD"
            pass





What is the best way to do this ?

Regards,

Dimitri

Dear listmembers,

I experienced a problem with matplotlib yesterday that caused me a lot of 
headache and I don't know whether this is a bug or if I forgot something.

What I want is to plot different datasets in different plots in different 
files. My code looks like that:

#######################

from pylab import fft, ifft, var, average, real, show
import matplotlib.pyplot as plt

def process_file(filename, fig_nr):    
    
    plt.figure(fig_nr)
    plt.clf()

    plt.subplot(211)      
    plt.plot(s, alt, '-')
    
    plt.subplot(212) 
    plt.plot(s,map(lambda x: x*3.6,speed))
    
    plt.savefig(filename+".png")
    
    
process_file("foo1.tcx", 1)
process_file("foo2.tcx", 2)
process_file("foo3.tcx",3)

##########################

The problem here is that in the plots for file foo2 the data from foo1 is 
included, in the plots for foo3 the data of foo1 and foo2.

I thought that I paid respect to this behaviour with plt.figure(), on 
stackoverflow I read about the plt.clf() - thing but nothing happened. I tried 
to make fig_nr a hash over the filename or leave it blank (like suggested in 
the documentation) but this had no effect and I ended up with the additional 
parameter (fig_nr in the example above) which also did not work.

Is this maybe a bug or did I forget an important thing?

I'm running Debian sid with python-matplotlib 0.99.1.2-2 (I hope the numbering 
from Debian and matplotlib is similar).

Best regards,
Philipp Bender

Jeff Whitaker wrote:
> Dr. Phillip M. Feldman wrote:
>> Jeff Whitaker wrote:
>>  
>>> <snip>
>>> Philip:  That's an error from the proj4 c library saying that it 
>>> didn't like one of the parameters you used to define the 
>>> projection.  Since you didn't include the parameters you used, I 
>>> can't say which one is the culprit.
>>>
>>> -Jeff
>>>
>>>     
>>
>>   
> Philip: I believe that lat_0 must be zero for the geostationary 
> projection (you have to be looking down on the equator).  I usually 
> leave the lat_0 parameter off entirely, in which case zero is 
> assumed.  I'll try to catch that and raise a more insightful error 
> message.
>
> -Jeff
>

Hm.  I suppose that you are right.  "Geostationary" does imply that the 
viewer is 35786.2 km above the equator.

What would be more useful is a geosynchronous projection.  This would 
allow the viewer to be located at any latitude.  Geostationary is a 
special case of geosynchronous.

Even more useful than a geosynchronous projection is a camera projection 
that allows one to place the viewer at any location in space (i.e., any 
latitude and longitude for the nadir point, and any altitude).  (I wrote 
something like this is Fortran 25 years ago).  Generalizing the existing 
geostationary projection to turn it into a camera projection would make 
it far more useful.  I hope that someone will consider making this change.

Phillip

Dr. Phillip M. Feldman wrote:
> Jeff Whitaker wrote:
>   
>> <snip>
>> Philip:  That's an error from the proj4 c library saying that it didn't 
>> like one of the parameters you used to define the projection.  Since you 
>> didn't include the parameters you used, I can't say which one is the 
>> culprit.
>>
>> -Jeff
>>
>>     
>
>   
Philip: I believe that lat_0 must be zero for the geostationary 
projection (you have to be looking down on the equator).  I usually 
leave the lat_0 parameter off entirely, in which case zero is assumed.  
I'll try to catch that and raise a more insightful error message.

-Jeff