Nobody has tried to do this (that I know of), so I can't point you to anything specific. Did you see my message about creating a gridded field (say 1's for points inside and 0's for points outside the region), the calling contour to draw the line? You can use the is_land method to determine if a point is over land or not, but there is not way to determine whether a given point is inside a country. As you found out, there is no metadata associated with the coastlines or political boundary lines.
The fillcontinents method returns a list matplotlib polygon instances that represent the land areas. One of them is North America, and could be used to clip your line segments - but there is no easy way to determine which one it is.
If you can find a shapefile that just contains a CONUS polygon, you could use that I suppose.
On 9/28/11 2:19 PM, Isidora wrote:
I have just seen your answers. I am trying to plot on a background GIF map, lines like the ones you can see in http://www.spc.noaa.gov/products/outlook/day1probotlk_2000_wind.gif. I can plot the lines as you see them in this link without a problem. However, because those lines are not closed polygons, the filling extends only to a straight line between first and last point of the curve.
I want the filling to extend all the way to the border of United States.
Since drawcountries() return a Collection of paths without any metadata identifying the country/countries been separated by it, I cannot use it to mask the area outside ofthe borders out.
I'd appreciate any link/documentation I could read to help me resolve this issue.
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