[Matplotlib-users] how to erase items in figures

[j v. <jim...@no...>]

Hello users,

I wish to repeatedly re-plot labels and contour data on a figure since 
redrawing the figure is temporally expensive.  The attached script (I 
apologize for its length), hopefully, illustrates a simplified version 
of what I'm trying to do -- contour temporally-varying data on a map 
projection.

I do not understand how to erase the plot label each time the figure is 
to be reused.  I also do not know how to erase the contour-fill 
although, based on the generated PNG files,  it does not, for unknown 
reasons , appear to be necessary.  From some postings, it seems that I 
have to employ collections attributes, but I have not been able to find 
documentation or examples that illustrate this.

My system:

    * matplotlib.__version__: '0.91.2'
    * sys.version: '2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC
      v.1310 32 bit (Intel)]'


Thanks,
-- jv