how can i make a contour plot with mask

hi,everybody.first say sorry for my poor english.
I want to make a contour plot with part out of the irregular boundary
blank.just as http://www.pyngl.ucar.edu/Examples/Images/ngl05p.3.png
shows.
how can i do?

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shuwj5460@...1221... wrote:

hi,everybody.first say sorry for my poor english.
I want to make a contour plot with part out of the irregular boundary
blank.just as http://www.pyngl.ucar.edu/Examples/Images/ngl05p.3.png
shows.
how can i do?

How is the irregular boundary defined? Is it defined in terms of the data you are plotting (i.e. all values exceeding a threshold)? Or, do you have the vertices of a polygon you want to use as a mask?

-Jeff

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Jeffrey S. Whitaker Phone : (303)497-6313
NOAA/OAR/CDC R/PSD1 FAX : (303)497-6449
325 Broadway Boulder, CO, USA 80305-3328

How is the irregular boundary defined? Is it defined in terms of the
data you are plotting (i.e. all values exceeding a threshold)? Or, do
you have the vertices of a polygon you want to use as a mask?

-Jeff

Jeff,
   thanks for answering my question. I have the vertices of a polygon
used as a mask.

                      shu

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