On 5/12/10 7:37 AM, Michael Hearne wrote:
> Jeff - That's great, thanks! For future releases, is there a reason why
> fillcontinents() couldn't do the logic for the user - i.e., if the continent
> fills the figure, paint it with the user's desired color? I think that's
> less surprising than the way it works now.
>
> --Mike
>
Mike: You're right, it is surprising behavior. The reason I did it
that way was because sometimes the polygon filling algorithm gets
confused when all four corners of the domain are in the polygon and
fills the whole map (even when it shouldn't). Since the cure is probably
worse than the disease in this case, I've turned this off in svn, so
your example works as expected.
-Jeff
>
> On May 11, 2010, at 2:22 PM, Jeff Whitaker wrote:
>
>
>> On 5/11/10 8:02 AM, Michael Hearne wrote:
>>
>>> Jeff - Thanks. Is there an easy way you know of to detect when there are
>>> no continent boundaries? I'm making these maps automatically, and so will
>>> not have the luxury of examining them to see where they are.
>>>
>>> --Mike
>>>
>>>
>> Mike: Unfortunately, there is no easy way to check since those computations
>> are only done when you call fillcontinents. Here's a function that follows
>> the logic in fillcontinents:
>>
>> def all_land(map):
>> for poly,type in zip(map.coastpolygons, map.coastpolygontypes):
>> if type == 1:
>> x, y = poly
>> xa = np.array(x,np.float32)
>> ya = np.array(y,np.float32)
>> # check to see if all four corners of domain in polygon (if so,
>> # don't draw since it will just fill in the whole map).
>> delx = 10; dely = 10
>> if map.projection in ['cyl']:
>> delx = 0.1
>> dely = 0.1
>> test1 = np.fabs(xa-map.urcrnrx)< delx
>> test2 = np.fabs(xa-map.llcrnrx)< delx
>> test3 = np.fabs(ya-map.urcrnry)< dely
>> test4 = np.fabs(ya-map.llcrnry)< dely
>> hasp1 = np.sum(test1*test3)
>> hasp2 = np.sum(test2*test3)
>> hasp4 = np.sum(test2*test4)
>> hasp3 = np.sum(test1*test4)
>> if not hasp1 or not hasp2 or not hasp3 or not hasp4:
>> allin = False
>> else:
>> allin = True
>> return allin
>>
>> If you pass this function the basemap instance, it should return True if no
>> coastline polygons will be drawn.
>>
>> -Jeff
>>
>>
>>> On May 10, 2010, at 2:57 PM, Jeff Whitaker wrote:
>>>
>>>
>>>
>>>> On 5/10/10 2:21 PM, Michael Hearne wrote:
>>>>
>>>>
>>>>> I have found a (possible) bug in Basemap - when using
>>>>> basemap.fillcontinents(), I see the chosen continent color only when the
>>>>> map I create includes some ocean. If I am in the interior of a continent
>>>>> (I've tested with North America and Asia), the continent color is white.
>>>>>
>>>>>
>>>>>
>>>> Michael: If there are no continent boundaries inside the map projection
>>>> region, basemap does not draw anything (hence you see the axis background
>>>> color). In that case, you should just set the axis background color to
>>>> whatever you wanted the continent color to be.
>>>>
>>>> -Jeff
>>>>
>>>>
>>>>> A code sample is below. My version information:
>>>>> Basemap: 0.99.4
>>>>> Matplotlib: 0.99.1.1
>>>>> numpy: 1.4.0
>>>>> Python: 2.6.4
>>>>>
>>>>> To replicate my results, please try the following:
>>>>> ./maptest.py 37.894507 -121.816406 #map center is somewhere in the Bay
>>>>> Area in California
>>>>> ./maptest.py 41.880332 -100.47821 #map center is somewhere in Nebraska
>>>>>
>>>>> The script creates a file called "output.png" in the calling directory.
>>>>> In the California case, I see the ocean as blue, and the land as a sort
>>>>> of annoying salmon color. In the Nebraska case, I see white with blue
>>>>> denoting the various rivers and lakes in the area.
>>>>>
>>>>> Am I mis-using the basemap method calls in some way?
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Mike
>>>>>
>>>>> --------------------------------------------------------------------
>>>>> #!/usr/bin/env python
>>>>>
>>>>> import matplotlib
>>>>> #use the non-interactive matplotlib setting
>>>>> matplotlib.use('agg')
>>>>> from mpl_toolkits.basemap import Basemap
>>>>> import numpy as np
>>>>> from pylab import *
>>>>> import sys
>>>>>
>>>>> clat = float(sys.argv[1])
>>>>> clon = float(sys.argv[2])
>>>>>
>>>>> figwidth = 5.4
>>>>>
>>>>>
>>>>> bounds = (clon-4, clon+4, clat-4, clat+4)
>>>>> dx = (bounds[1] - bounds[0])*111191 * np.cos(clat * np.pi/180)
>>>>> dy = (bounds[3] - bounds[2])*111191
>>>>> aspect = dy/dx
>>>>> figheight = aspect * figwidth
>>>>>
>>>>> fig = figure(figsize=(figwidth,figheight),edgecolor='g',facecolor='g')
>>>>> ax1 = fig.add_axes([0,0,1.0,1.0])
>>>>> mapcontour = Basemap(llcrnrlon=bounds[0],llcrnrlat=bounds[2],
>>>>> urcrnrlon=bounds[1],urcrnrlat=bounds[3],
>>>>> resolution='h',projection='merc',lat_ts=clat)
>>>>> water_color = [.47,.60,.81]
>>>>> mapcontour.drawrivers(color=water_color)
>>>>> mapcontour.drawcountries(color='k',linewidth=2.0)
>>>>> mapcontour.drawcoastlines()
>>>>> mapcontour.fillcontinents(color=[1.0,0.8,0.8],lake_color=water_color)
>>>>>
>>>>> plt.savefig('output.png')
>>>>> --------------------------------------------------------------------
>>>>>
>>>>>
>>>>> ------------------------------------------------------------------------------
>>>>>
>>>>> _______________________________________________
>>>>> Matplotlib-users mailing list
>>>>> Matplotlib-users@lists.sourceforge.net
>>>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>
>> --
>> Jeffrey S. Whitaker Phone : (303)497-6313
>> Meteorologist FAX : (303)497-6449
>> NOAA/OAR/PSD R/PSD1 Email : jeffrey.s.whita...@noaa.gov
>> 325 Broadway Office : Skaggs Research Cntr 1D-113
>> Boulder, CO, USA 80303-3328 Web : http://tinyurl.com/5telg
>>
>>
>
--
Jeffrey S. Whitaker Phone : (303)497-6313
Meteorologist FAX : (303)497-6449
NOAA/OAR/PSD R/PSD1 Email : jeffrey.s.whita...@noaa.gov
325 Broadway Office : Skaggs Research Cntr 1D-113
Boulder, CO, USA 80303-3328 Web : http://tinyurl.com/5telg
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