Re: [Matplotlib-users] basemap does not draw coastlines for certain choice of map boundaries

[Jeff Whitaker]

Sourish Basu May 8, 2013 5:50 AM Hi all, I discovered recently that basmap does not draw the coastline contours properly for some choice of map boundaries. Specifically, from mpl_toolkits.basemap import Basemap map = Basemap(projection='cyl',llcrnrlat=-22.,urcrnrlat=22.,llcrnrlon=78.,urcrnrlon=168.,resolution='l') map.drawcoastlines() results in the coastline of continental Asia not being drawn (see attachment bad_contours.png). On the other hand, even subtly changing the latitude boundaries, to map = Basemap(projection='cyl',llcrnrlat=-22.001,urcrnrlat=22.001,llcrnrlon=78.,urcrnrlon=168.,resolution='l') results in all the coastlines being drawn (see attachment good_contours.png). I presume this is a bug? Sourish:  Yes, this is a bug.  There are some corner cases in which the algorithm that clips the coastline polygons to the map projection region fails. I've never been able to figure out exactly why.   You solution (of slightly changing the map projection region) is the only thing I can recommend for now. -Jeff Here is my system info: Operating system: Linux 3.2.0-41-generic #66-Ubuntu SMP Thu Apr 25 03:27:11 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux Matplotlib version: 1.1.0 Where I obtained matplotlib: SourceForge Customizations to matplotlibrc: none Thanks, Sourish ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. This 200-page book is written by three acclaimed leaders in the field. The early access version is available now. Download your free book today! http://p.sf.net/sfu/neotech_d2d_may _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users

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Learn Graph Databases - Download FREE O'Reilly Book
"Graph Databases" is the definitive new guide to graph databases and 
their applications. This 200-page book is written by three acclaimed 
leaders in the field. The early access version is available now. 
Download your free book today! http://p.sf.net/sfu/neotech_d2d_may
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