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Jeff - I think the way GMT does it would be okay - they have a 
latitude of true scale, which I usually choose as the center latitude 
of the map.
I was thinking we should allow people to choose the "simple" or 
"fancy" options. Do you think it will be okay to have the height of 
the bar and the text offset be relative to the length of it? I 
suppose if the height becomes a problem, people could use the yoffset 
keyword...
--Mike
On Mar 4, 2008, at 6:05 AM, Jeff Whitaker wrote:
> Michael Hearne wrote:
>> Jeff - That would replicate the "simple" scale-bar from GMT. 
>> Below is my not-complete attempt at replicating the "fancy" scale 
>> bar. It would need some options for specifying different units 
>> (miles, nautical miles, etc.) and perhaps some more attention to 
>> spacing of the text from the scale bar and tick marks...
>>
>> --Mike
>
> Mike: Very nice! Do you want the scale to show the true distance 
> on the earth (in which case the labels will vary depending on where 
> the label is placed), or the distance in map projection coordinates 
> (in which case the labels are constant)? Or perhaps a lat/lon 
> value could be given to specify where the scale is true?
>
> -Jeff
>>
>> from numpy import *
>> from matplotlib.toolkits.basemap import Basemap, pyproj
>> from pylab import *
>> # add drawscale method to Basemap class.
>> class Basemap2(Basemap):
>> def drawscale(self,lon,lat,length,yoffset=None):
>> """draw a fancy map scale from lon-length/2,lat-yoffset to
>> lon-length/2,lat-yoffset, label it with actual distance in 
>> km"""
>> length = length*1000 #input length is km
>>
>> #we need 5 sets of x coordinates (in map units)
>> #center of scale
>> xc,yc = self(lon,lat)
>> #left edge of scale
>> lon1,lat1 = self(xc-length/2,yc,inverse=True)
>> x1,y1 = self(lon1,lat1)
>> #quarter scale
>> lon2,lat2 = self(xc-length/4,yc,inverse=True)
>> x2,y2 = self(lon2,lat2)
>> #three quarter scale
>> lon3,lat3 = self(xc+length/4,yc,inverse=True)
>> x3,y3 = self(lon3,lat3)
>> #right edge of scale
>> lon4,lat4 = self(xc+length/2,yc,inverse=True)
>> x4,y4 = self(lon4,lat4)
>> if yoffset is None: yoffset = 0.1*length
>>
>> #plot top line
>> ytop = yc+yoffset/2
>> ybottom = yc-yoffset/2
>> ytick = ybottom - yoffset/2
>> ytext = ytick - yoffset/2
>> m.plot([x1,x4],[ytop,ytop],color='k')
>> #plot bottom line
>> m.plot([x1,x4],[ybottom,ybottom],color='k')
>> #plot left edge
>> m.plot([x1,x1],[ybottom,ytop],color='k')
>> #plot right edge
>> m.plot([x4,x4],[ybottom,ytop],color='k')
>>
>> #make a filled black box from left edge to 1/4 way across
>> fill([x1,x2,x2,x1,x1],[ytop,ytop,ybottom,ybottom,ytop],'k')
>> #make a filled white box from 1/4 way across to 1/2 way across
>> fill([x2,xc,xc,x2,x2],[ytop,ytop,ybottom,ybottom,ytop],'w')
>> #make a filled white box from 1/2 way across to 3/4 way across
>> fill([xc,x3,x3,xc,xc],[ytop,ytop,ybottom,ybottom,ytop],'k')
>> #make a filled white box from 3/4 way across to end
>> fill([x3,x4,x4,x3,x3],[ytop,ytop,ybottom,ybottom,ytop],'w')
>> #plot 3 tick marks at left edge, center, and right edge
>> m.plot([x1,x1],[ytick,ybottom],color='k')
>> m.plot([xc,xc],[ytick,ybottom],color='k')
>> m.plot([x4,x4],[ytick,ybottom],color='k')
>>
>> #label 3 tick marks
>> text(x1,ytext,'%d' % (0),\
>> horizontalalignment='center',\
>> verticalalignment='top',\
>> fontsize=9)
>> text(xc,ytext,'%d' % (round((length/2)/1000)),\
>> horizontalalignment='center',\
>> verticalalignment='top',\
>> fontsize=9)
>> text(x4,ytext,'%d' % (round((length)/1000)),\
>> horizontalalignment='center',\
>> verticalalignment='top',\
>> fontsize=9)
>>
>> #put units on top
>> text(xc,ytop+yoffset/2,'km',\
>> horizontalalignment='center',\
>> verticalalignment='bottom',\
>> fontsize=9)
>>
>> # setup of basemap ('lcc' = lambert conformal conic).
>> # use major and minor sphere radii from WGS84 ellipsoid.
>> m = Basemap2 
>> (llcrnrlon=-145.5,llcrnrlat=1.,urcrnrlon=-2.566,urcrnrlat=46.352,\
>> rsphere=(6378137.00,6356752.3142),\
>> resolution='l',area_thresh=1000.,projection='lcc',\
>> lat_1=50.,lon_0=-107.)
>> # draw coastlines and political boundaries.
>> m.drawcoastlines()
>> m.fillcontinents()
>> # draw parallels and meridians.
>> # label on left, right and bottom of map.
>> m.drawparallels(arange(0.,80,20.),labels=[1,1,0,1])
>> m.drawmeridians(arange(10.,360.,30.),labels=[1,1,0,1])
>> # draw a line from x1,y to x2,y and label it with distance in km.
>> length = 3000 #kilometers
>> x1,y1 = 0.25*m.xmax, 0.25*m.ymax
>> lon1,lat1 = m(x1,y1,inverse=True)
>> m.drawscale(lon1,lat1,length)
>> title('a fancy map scale')
>> show()
>>
>>
>>
>>
>> ------------------------------------------------------
>> Michael Hearne
>> mh...@us... <mailto:mh...@us...>
>> (303) 273-8620
>> USGS National Earthquake Information Center
>> 1711 Illinois St. Golden CO 80401
>> Senior Software Engineer
>> Synergetics, Inc.
>> ------------------------------------------------------
>>
>>
>
>
> -- 
> Jeffrey S. Whitaker Phone : (303)497-6313
> NOAA/OAR/CDC R/PSD1 FAX : (303)497-6449
> 325 Broadway Boulder, CO, USA 80305-3328
------------------------------------------------------
Michael Hearne
mh...@us...
(303) 273-8620
USGS National Earthquake Information Center
1711 Illinois St. Golden CO 80401
Senior Software Engineer
Synergetics, Inc.
------------------------------------------------------

Like your last question, I think you're using the current release's 
documentation (0.91.2) with an old release (probably 0.90.1 or earlier).
pyplot did not exist in 0.90.1, but I believe everything that is now in 
pyplot used to be in pylab, so you could just import that instead.
Cheers,
Mike
Ssebuliba, J, Mnr <jo...@su...> wrote:
> Hi there,
> 
> When I use;
> 
> import matplotlib.pyplot as p, 
> 
> I get an error message;
> 
> ImportError: No module named pyplot. So, how am I supposed to get these missing modules?
> 
> Please note: I am using Linux (Ubuntu-gusty)!
> 
> Regards,
> JOE.
> 
> -------------------------------------------------------------------------
> This SF.net email is sponsored by: Microsoft
> Defy all challenges. Microsoft(R) Visual Studio 2008.
> http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
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-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

It looks as if you're using 0.90.1. All of these issues are fixed in 
0.91.2. If you can upgrade, that's probably your best bet.
Or, if you have all the requirements, you can set "text.usetex" to True 
in your matplotlibrc which will use the "real" TeX on your system to 
typeset math -- that should support your expression.
Ssebuliba, J, Mnr <jo...@su...> wrote:
> Hi all,
> 
> When I use;
> text(0.6, 0.6, r'$\mathcal{A}\mathrm{sin}(2 \omega t)$', fontsize=20)
> 
> I get an error message below;
> File "/usr/lib/python2.5/site-packages/matplotlib/mathtext.py", line 616, in _get_info
> raise ValueError('unrecognized symbol "%s"' % sym)
> ValueError: unrecognized symbol "\mathr", unrecognized symbol "\mathcal"
0.90.1 was much less TeX-like in its mathtext support, and therefore 
doesn't support \mathrm, \mathcal etc.. You can, however do:
text(0.6, 0.6, r'$\cal{A}\rm{sin}(2 \omega t)$', fontsize=20)
which works for me.
> When I replace \mathrm with \mbox or \text, the error message I get is basically the same, only that this time, the last line appears as;
> unrecognized symbol "\mbox", unrecognized symbol "\text"
\mbox and \text aren't supported by the built-in mathtext in any version.
Cheers,
Mike
-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

Michael Hearne wrote:
> Jeff - That would replicate the "simple" scale-bar from GMT. Below is 
> my not-complete attempt at replicating the "fancy" scale bar. It 
> would need some options for specifying different units (miles, 
> nautical miles, etc.) and perhaps some more attention to spacing of 
> the text from the scale bar and tick marks...
>
> --Mike
Mike: Very nice! Do you want the scale to show the true distance on 
the earth (in which case the labels will vary depending on where the 
label is placed), or the distance in map projection coordinates (in 
which case the labels are constant)? Or perhaps a lat/lon value could 
be given to specify where the scale is true?
-Jeff
>
> from numpy import *
> from matplotlib.toolkits.basemap import Basemap, pyproj
> from pylab import *
> # add drawscale method to Basemap class.
> class Basemap2(Basemap):
> def drawscale(self,lon,lat,length,yoffset=None):
> """draw a fancy map scale from lon-length/2,lat-yoffset to
> lon-length/2,lat-yoffset, label it with actual distance in km"""
> length = length*1000 #input length is km
>
> #we need 5 sets of x coordinates (in map units)
> #center of scale
> xc,yc = self(lon,lat)
> #left edge of scale
> lon1,lat1 = self(xc-length/2,yc,inverse=True)
> x1,y1 = self(lon1,lat1)
> #quarter scale
> lon2,lat2 = self(xc-length/4,yc,inverse=True)
> x2,y2 = self(lon2,lat2)
> #three quarter scale
> lon3,lat3 = self(xc+length/4,yc,inverse=True)
> x3,y3 = self(lon3,lat3)
> #right edge of scale
> lon4,lat4 = self(xc+length/2,yc,inverse=True)
> x4,y4 = self(lon4,lat4)
> 
> if yoffset is None: yoffset = 0.1*length
>
> #plot top line
> ytop = yc+yoffset/2
> ybottom = yc-yoffset/2
> ytick = ybottom - yoffset/2
> ytext = ytick - yoffset/2
> m.plot([x1,x4],[ytop,ytop],color='k')
> #plot bottom line
> m.plot([x1,x4],[ybottom,ybottom],color='k')
> #plot left edge
> m.plot([x1,x1],[ybottom,ytop],color='k')
> #plot right edge
> m.plot([x4,x4],[ybottom,ytop],color='k')
>
> #make a filled black box from left edge to 1/4 way across
> fill([x1,x2,x2,x1,x1],[ytop,ytop,ybottom,ybottom,ytop],'k')
> #make a filled white box from 1/4 way across to 1/2 way across
> fill([x2,xc,xc,x2,x2],[ytop,ytop,ybottom,ybottom,ytop],'w')
> #make a filled white box from 1/2 way across to 3/4 way across
> fill([xc,x3,x3,xc,xc],[ytop,ytop,ybottom,ybottom,ytop],'k')
> #make a filled white box from 3/4 way across to end
> fill([x3,x4,x4,x3,x3],[ytop,ytop,ybottom,ybottom,ytop],'w')
> 
> #plot 3 tick marks at left edge, center, and right edge
> m.plot([x1,x1],[ytick,ybottom],color='k')
> m.plot([xc,xc],[ytick,ybottom],color='k')
> m.plot([x4,x4],[ytick,ybottom],color='k')
>
> #label 3 tick marks
> text(x1,ytext,'%d' % (0),\
> horizontalalignment='center',\
> verticalalignment='top',\
> fontsize=9)
> text(xc,ytext,'%d' % (round((length/2)/1000)),\
> horizontalalignment='center',\
> verticalalignment='top',\
> fontsize=9)
> text(x4,ytext,'%d' % (round((length)/1000)),\
> horizontalalignment='center',\
> verticalalignment='top',\
> fontsize=9)
>
> #put units on top
> text(xc,ytop+yoffset/2,'km',\
> horizontalalignment='center',\
> verticalalignment='bottom',\
> fontsize=9)
>
> # setup of basemap ('lcc' = lambert conformal conic).
> # use major and minor sphere radii from WGS84 ellipsoid.
> m = 
> Basemap2(llcrnrlon=-145.5,llcrnrlat=1.,urcrnrlon=-2.566,urcrnrlat=46.352,\
> rsphere=(6378137.00,6356752.3142),\
> resolution='l',area_thresh=1000.,projection='lcc',\
> lat_1=50.,lon_0=-107.)
> # draw coastlines and political boundaries.
> m.drawcoastlines()
> m.fillcontinents()
> # draw parallels and meridians.
> # label on left, right and bottom of map.
> m.drawparallels(arange(0.,80,20.),labels=[1,1,0,1])
> m.drawmeridians(arange(10.,360.,30.),labels=[1,1,0,1])
> # draw a line from x1,y to x2,y and label it with distance in km.
> length = 3000 #kilometers
> x1,y1 = 0.25*m.xmax, 0.25*m.ymax
> lon1,lat1 = m(x1,y1,inverse=True)
> m.drawscale(lon1,lat1,length)
> title('a fancy map scale')
> show()
>
>
>
>
> ------------------------------------------------------
> Michael Hearne
> mh...@us... <mailto:mh...@us...>
> (303) 273-8620
> USGS National Earthquake Information Center
> 1711 Illinois St. Golden CO 80401
> Senior Software Engineer
> Synergetics, Inc.
> ------------------------------------------------------
>
>
-- 
Jeffrey S. Whitaker Phone : (303)497-6313
NOAA/OAR/CDC R/PSD1 FAX : (303)497-6449
325 Broadway Boulder, CO, USA 80305-3328

Hi there,
When I use;
import matplotlib.pyplot as p, 
I get an error message;
ImportError: No module named pyplot. So, how am I supposed to get these missing modules?
Please note: I am using Linux (Ubuntu-gusty)!
Regards,
JOE.

Hi all,
When I use;
text(0.6, 0.6, r'$\mathcal{A}\mathrm{sin}(2 \omega t)$', fontsize=20)
I get an error message below;
File "/usr/lib/python2.5/site-packages/matplotlib/mathtext.py", line 616, in _get_info
 raise ValueError('unrecognized symbol "%s"' % sym)
ValueError: unrecognized symbol "\mathr", unrecognized symbol "\mathcal"
When I replace \mathrm with \mbox or \text, the error message I get is basically the same, only that this time, the last line appears as;
unrecognized symbol "\mbox", unrecognized symbol "\text"
How should I fix this problem?
Many thanks,
JOE.

How use numpy in order to create Image object from string ?
.
.
.
size = canvas.get_width_height( )
buffer = canvas.tostring_rgb()
img = numpy.empty(size,numpy.uint32)
img = numpy.fromstring(buffer,numpy.uint32)
img is an array , but I want an Image object (without using PIL ).
sa6113 wrote:
> 
> Would you please help me ?
> I want to load data to Image (QImage) from String or binary String without
> using PIL module .
> 
-- 
View this message in context: http://www.nabble.com/how-load-data-to-Image-from-String--tp15784115p15822415.html
Sent from the matplotlib - users mailing list archive at Nabble.com.

Is there anyway to use the modules that are already on the system, or those
that are pure Python ?
I want to show a plot that draws with backend agg in my GUI , I mean in a
specified place that its type is Qlabel or QFrame , I don't want to save the
plot befor show it.
Christopher Barker wrote:
> 
> sa6113 wrote:
>> Would you please help me ?
>> I want to load data to Image (QImage) from String or binary String
>> without
>> using PIL module .
> 
> you can load data straight into a numpy array with numpy.fromstring() -- 
> if it's in an easy format (RGB, RGBA), then you should be able to go 
> from there.
> 
> What do you want to do with the image data?
> 
> -CHB
> 
> 
> -- 
> Christopher Barker, Ph.D.
> Oceanographer
> 
> Emergency Response Division
> NOAA/NOS/OR&R (206) 526-6959 voice
> 7600 Sand Point Way NE (206) 526-6329 fax
> Seattle, WA 98115 (206) 526-6317 main reception
> 
> Chr...@no...
> 
> -------------------------------------------------------------------------
> This SF.net email is sponsored by: Microsoft
> Defy all challenges. Microsoft(R) Visual Studio 2008.
> http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
> 
> 
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Sent from the matplotlib - users mailing list archive at Nabble.com.

Hi, I'm trying to use the values of a contour plot to evaluate the min/max
along a given axis in order to marginalize a 2d distribution. This
effectively amounts to doing the same thing asked for in this post:
http://sourceforge.net/mailarchive/message.php?msg_id=47505681.8030306%40hawaii.edu
I think there's an easier way to do this:
val = contour(xRange,yRange,delchi2,[1])
t = asarray(val.collections[0].get_verts())
because the example given in the above post actually return a list, not a
numpy array (unless I did it wrong).
However, even though the above works, it was poorly documented and took
about an hour of googling / guess-and-checking to get to it. Either the
documentation should be improved a little (e.g. explain what "collections"
really means) or some more transparent means of returning the contour data
should be available.
So, the question: is there any easier way to do the above? Is this actually
the easy method?
Thanks,
Adam