Hatch, Sara J wrote: > > Matplotlib Folks, > > I tried to use the orthographic projection in the basemap toolkit and > I’m finding that the parallel lines are not behaving correctly, i.e., > there are horizontal lines connecting the left and right side of the > map boundary where a curved latitude line intersects the map boundary. > I’ve included a sample script below and a figure illustrating the problem. > > import pylab > > import mpl_toolkits.basemap as basemap > > ortho = > basemap.Basemap(projection='ortho',lon_0=0,lat_0=50,rsphere=1737.4) > > ortho.drawparallels(pylab.arange(-90,90,30)) > > ortho.drawmeridians(pylab.arange(0,360,30)) > > ortho.drawmapboundary(fill_color='w') > > In addition, how do I change the x/y coordinates the center of the > projection to be (0,0)? With the above code, the center of the > bounding circle is at (1737.4,1737.4). > > Thanks for the help, > > Sara > Sara: If you take out the rsphere=1734.4 (thereby using the default value of 6370997), the jumpy lines go away. rsphere=1734.4 means assume the earth is a perfect sphere with a radius of 1734.4 meters. That's an awfully small earth - I think the jumpy lines are a result of roundoff errors in the map projection calculation for very small spheres. Still, that shouldn't happen, so I will look into it.
Regarding the x/y coordinate of the middle of the plot - Basemap assigns the lower left corner of the map projection region an x/y value of 0,0 for most map projections. -Jeff ------------------------------------------------------------------------------ Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are powering Web 2.0 with engaging, cross-platform capabilities. Quickly and easily build your RIAs with Flex Builder, the Eclipse(TM)based development software that enables intelligent coding and step-through debugging. Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
