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thanks for this link Scott, I went into the refernce API directly 
without looking at this tutorial. Effectively, it works :-)

Scott Sinclair a écrit :
>>>> Lionel Roubeyrie <lro...@li...> 07/23/08 9:37 AM >>>
>>>>         
> I want to "convert" a filled contours map generated with 
> Basemap (example here : http://imagebin.ca/view/3nYnN3.html)
> to a polygon shapefile (vector). 
>
> After multiple tests, I can retrieve the polygons points coordinates via 
> matplotlib.Patch and save them in a shp file. Now I have troubles with 
> "real" coordinates and meta-datas, but nothing impossible :-)
>   
>
> Hi,
>
> If you're after a 'quick and dirty' solution.
>
> As I understand it a KML file can be used to specify the Latitude and Longitude extent of a raster image (See 'Ground Overlays' at http://code.google.com/apis/kml/documentation/kml_tut.html). If you can accept some distortion of the text on your image (should be small with a small region) and can work out the size of each pixel in degrees of lat and lon, then all you need to do is write a simple text file to specify where Google Earth should display your Basemap contour map.
>
> What you're doing does sound more elegant, but more complex.
>
> Regards,
> Scott
>
>
>
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On Wed, Jul 23, 2008 at 9:06 AM, Jonathan Hayward http://JonathansCorner.com
>>  fig = figure((8,6), dpi=100)  # 800x600
>
> When I tried placing that line in a couple of places, I got an error:

Sorry, my fault, you need the keyword argument figsize:


In [1]: import matplotlib.pyplot as plt

In [2]: fig = plt.figure(figsize=(8,6), dpi=100)  # 800x600

On Tue, Jul 22, 2008 at 4:54 PM, John Hunter <jd...@gm...> wrote:

> On Tue, Jul 22, 2008 at 4:06 PM, Jonathan Hayward
> http://JonathansCorner.com <jon...@po...> wrote:
> > Thank you; I've shrunk the graphic part.
>
> Please respond to the mailing list ("reply to all")
>

Oops; sorry.

>
>
> > When I save it as an image, it's painting an 800x600 image, so I've
> shrunk
> > the portion of the 800x600 image I'm using. Is there a way to crop or do
> > something comparable?
>
> Not sure I understand the question.  You can control the figure size
> in pixels by setting the figure size in inches and the dpi -- the
> pixel size is the prodict of the two
>
>  fig = figure((8,6), dpi=100)  # 800x600
>

When I tried placing that line in a couple of places, I got an error:

jhayward@jhayward-desktop ~/bin $ ./barchart
Traceback (most recent call last):
  File "./barchart", line 6, in ?
    fig = figure((8,6), dpi=100)
  File "/usr/lib/python2.4/site-packages/matplotlib/pyplot.py", line 186, in
figure
    FigureClass=FigureClass,
  File
"/usr/lib/python2.4/site-packages/matplotlib/backends/backend_gtkagg.py",
line 44, in new_figure_manager
    return FigureManagerGTKAgg(canvas, num)
  File
"/usr/lib/python2.4/site-packages/matplotlib/backends/backend_gtk.py", line
405, in __init__
    self.window.set_title("Figure %d" % num)
TypeError: not all arguments converted during string formatting

Are there other things it needs? (I tried placing a space so "8,6" would
read "8, 6", but it didn't significantly change the error.)

>
> you can control the *relative* proportion of the axes by using the
> axes command as before
>
>  ax = axes([left, bottom, width, height])
>
> with these two, you should be able to get whatever size and
> proportions you want.
>
> JDH
>



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>>> Lionel Roubeyrie <lro...@li...> 07/23/08 9:37 AM >>>
I want to "convert" a filled contours map generated with 
Basemap (example here : http://imagebin.ca/view/3nYnN3.html)
to a polygon shapefile (vector). 

After multiple tests, I can retrieve the polygons points coordinates via 
matplotlib.Patch and save them in a shp file. Now I have troubles with 
"real" coordinates and meta-datas, but nothing impossible :-)
>>>

Hi,

If you're after a 'quick and dirty' solution.

As I understand it a KML file can be used to specify the Latitude and Longitude extent of a raster image (See 'Ground Overlays' at http://code.google.com/apis/kml/documentation/kml_tut.html). If you can accept some distortion of the text on your image (should be small with a small region) and can work out the size of each pixel in degrees of lat and lon, then all you need to do is write a simple text file to specify where Google Earth should display your Basemap contour map.

What you're doing does sound more elegant, but more complex.

Regards,
Scott



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Thanks,
This unicode thing works like magic.
The only thing I am still unable to do is to insert the symbol \epsilon (as
distinct from \varepsilon).
For some reason, the varepsilon ε is printed fine, but a blank square is
printed instead of the lunate epsilon ϵ.
That is u' ε ' works,  while u' ϵ' does not.

Any idea why this is happening ?

Eli


2008/7/22 Michael Droettboom <md...@st...>:

> Yes, you would put it at the top of your .py file.
>
> In order to use Unicode in Python source code, you have to tell the Python
> interpreter what encoding the file is in.  That's done with a little "magic"
> comment at the top of the file.  The popular Unixy editors (emacs, vim etc.)
> also understand this comment and will save the file correctly.  Possibly
> other editors do as well.
>
> For more gory details that you probably need, see this:
>
> http://www.amk.ca/python/howto/unicode
>
> particularly the section "Unicode Literals in Python Source Code".
>
> Cheers,
> Mike
>
> Eli Brosh wrote:
>
>> Thanks,
>> This seems to be a solution.
>> I have an editor that supports unicode.
>> But, can you please explain better how do I make the coding directive at
>> the top of my source files ?
>> Where do I write the command:
>> # -*- coding: utf-8 -*-
>>
>> Is it inside the python script ?
>>
>>
>> Sorry for the ignorance.
>> Eli
>>
>> On Tue, Jul 22, 2008 at 10:14 AM, Michael Droettboom <md...@st...<mailto:
>> md...@st...>> wrote:
>>
>>    As an alternative, you could just use Unicode to insert the Greek
>>    characters:
>>
>>    r"α-Fe (Someone 2003)"
>>
>>    The default font used by matplotlib, Vera Sans, includes a full
>>    set of Greek characters. This, of course, requires an editor that
>>    supports Unicode and a coding directive at the top of your source
>>    files, eg.:
>>
>>    # -*- coding: utf-8 -*-
>>
>>
>>    Cheers,
>>    Mike
>>
>>    Eli Brosh wrote:
>>
>>        Here is the use case I have in mind:
>>        Plotting properties of various phases of iron, I need a legend
>>        with greek letters and normal text:
>>        \alpha-Fe, Someone (2003)
>>
>>        Now, I need the names e.g. someone to be upright.
>>        Also, the relbar between \alpha and Fe is shorter with normal
>>        text fonts than with italics.
>>
>>        I can solve the problem by using r'\rm{\alpha-Fe, Someone
>>        (2003)}' but it would be easier if I could just change the
>>        defaults.
>>
>>        Eli
>>
>>
>>        On Mon, Jul 21, 2008 at 6:21 PM, Michael Droettboom
>>        <md...@st... <mailto:md...@st...>
>>        <mailto:md...@st... <mailto:md...@st...>>> wrote:
>>
>>           Unfortunately there isn't. This is *theoretically* possible
>>        with
>>           the STIX fonts, but that hasn't been implemented. However, with
>>           the Computer Modern fonts, many of the glyphs simply aren't
>>           present (upright Greek, for example) to make this happen.
>>
>>           That said, I'm not sure this is necessarily a good idea.
>>        Math has
>>           a set of commonly accepted conventions about when to use italic
>>           vs. upright that may only confuse the reader when not followed.
>>           Can you provide a use case?
>>
>>           Cheers,
>>           Mike
>>
>>           Eli Brosh wrote:
>>
>>               Hello
>>               I there a way to change the default mathtext font from
>>        cal to rm ?
>>               I would like to use the rm (serif) font without stating
>>               rm{...} or mathrm{...}.
>>               Is it possible to do using the matplotlibrc ?
>>               can you give me an example of how this is done ?
>>
>>               Thanks
>>               Eli
>>
>> ------------------------------------------------------------------------
>>
>>
>> -------------------------------------------------------------------------
>>               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
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>>        anywhere
>>               in the world
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>>
>>
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>>
>>
>>
>>
>>    --    Michael Droettboom
>>    Science Software Branch
>>    Operations and Engineering Division
>>    Space Telescope Science Institute
>>    Operated by AURA for NASA
>>
>>
>>
> --
> Michael Droettboom
> Science Software Branch
> Operations and Engineering Division
> Space Telescope Science Institute
> Operated by AURA for NASA
>
>

Hi Tim,
like I said, I want to "convert" a filled contours map generated with 
Basemap (example here : http://imagebin.ca/view/3nYnN3.html)
to a polygon shapefile (vector). The filled contours are from a regular 
points grid which can already be saved into a point shapefile (via ogr 
python bindings)
and I use QGIS to render it. Now I search to get the filled result into 
a shp file to pass it through "ogr2ogr -f KML" and render it with 
GoogleEarth.
I know I can do all this process with the QGIS-GRASS interface, but I 
must limit softwares dependencies 'cause it'll be placed on a web 
server, and I think Python it's the best choice for doing that :-)
After multiple tests, I can retrieve the polygons points coordinates via 
matplotlib.Patch and save them in a shp file. Now I have troubles with 
"real" coordinates and meta-datas, but nothing impossible :-)

Tim Michelsen a écrit :
>> Looks like I've done a mistake with my last post, sorry Eli...
>> I know how to save datas to a shapefile with the OGR library but only 
>> for points datas.
>>     
>
>
>   
>> I'll appreciate if somebody can point me how to save a filled contour 
>> map basemap into a polygon shapefile, can't find any example with google.
>>     
> What do you really want to save here?
> A basemap with a contour surface overlayed can be viewed as a assembly 
> of various layers. So this is like the result of the gis operations when 
> you launch the map composer to finish your map.
>
> If you want to create a raster file from the contour part plotted over a 
> basemap I think the python bindings of gdal will get you started.
> http://pypi.python.org/pypi/GDAL/
> I succeded into writing a tiff file from a gdal array.
>
> I don't know how to write a vector file from python with ogr or shapely. 
>   But these questions are better to be asked on the gdal list.:
>
> So about interpolating to a contour look at shapely. Writing should be 
> accomplished with ogr.
>
> That said, I only have testing "experience" with writing geodata with 
> python.
>
> The overkill may be to invoke the respective GRASS command by a script.
>
> I would appreciate if you would tell us what you use by the end.
>
> Kind regards,
> Timmie
>
>
> When it comes to python and GIS the first stop seems to be:
>
> * http://gispython.org/
> * http://lists.gispython.org/mailman/listinfo/community
>
> Some more links:
> * http://de.giswiki.net/wiki/Kategorie:Python
> * http://de.giswiki.net/wiki/WorldMill
> * http://zcologia.com/news/750/keytree/
> * http://sgillies.net/
>
>
> -------------------------------------------------------------------------
> 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
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>
>
>   

-- 
Lionel Roubeyrie - lro...@li...
Chargé d'études et de maintenance
LIMAIR - la Surveillance de l'Air en Limousin
http://www.limair.asso.fr