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
>>> [email protected]
>>> 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 : [email protected]
325 Broadway Office : Skaggs Research Cntr 1D-113
Boulder, CO, USA 80303-3328 Web : http://tinyurl.com/5telg
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