[Matplotlib-users] plotting filled lines with missing data?

[Chris W. <ch...@si...>]

Eric Firing wrote:
> This is not doing what you think it is,

Indeed, I guess I was seeing nans being treated as missing values rather 
than being masked...

> You should use numpy.masked_where(numpy.isnan(aa), aa).

I am now ;-)

However, I'm still running into problems when I try and plot the gappy 
data on a filled line as follows:

dates = *an array of datetimes*
values = *an array containing data values and a few nans*
values = numpy.ma.masked_where(numpy.isnan(values),values)
xs,ys = mlab.poly_between(dates,0,values)
pylab.fill(xs,ys,'r')

For starters, I get this warning:

numpy\core\ma.py:609: UserWarning: Cannot automatically convert masked 
array to numeric because data is masked in one or more locations.

...and wherever a NaN occurs in the data, the line is plotted off the 
top of the axes. I want it to appear at 0 if there's no data. Well, 
ideally just not appear at all, but I'd settle for appearing at 0...

Any ideas?

cheers,

Chris

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