Re: [matplotlib-devel] spy: ignore zero values in sparse matrix

[John H. <jd...@gm...>]

On Fri, Sep 26, 2008 at 2:36 PM, Tony S Yu <to...@mi...> wrote:

> I guess you could plot sparse all-zero matrices with image mode.  My only
> hesitation is that sparse arrays tend to be very large and (I imagine) this
> would lead to very slow performance. I assumed this was the reason image
> mode wasn't adapted to use sparse arrays.
>
> Actually, now that I think about it: you could plot a trivially small image
> and just adjust the coordinates so that they correspond to the original
> matrix shape. Is this what you were thinking?

This is something I considered, but I was thinking less about the
implementation and more about the functionality.  I don't want to
raise an exception unless the input doesn't make sense.  I would
rather the user start at a boring image and figure out why it is blank
that deal with an exception.

> I should note that a dense zero array also fails to plot with spy *if marker
> mode is used*.

Can you fix this along with spy2?

JDH