[Matplotlib-users] Re: Matplotlib

[John H. <jdh...@ac...>]

>>>>> "Steve" == Steve Chaplin <ste...@ya...> writes:

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    Steve> I've been having a look at Matplotlib recently and have
    Steve> found it quite useful.

    Steve> I noticed that in backend_gtk.py the function pany() does
    Steve> not have 'return gtk.TRUE', whereas panx() does.

Hi Steve, 

Thanks for pointing out the inconsistency.  I just updated the code.
Also, the zoom in/out tools are reversed in the last release of
matplotib.  This is fixed in CVS.

    Steve> I understand that Numercial Python will be superseded by
    Steve> Numarray, is there a plan to allow Numarray to be used with
    Steve> Matplotlib?  Is it a straightforward substitution,
    Steve> something like 'from numarray import *' instead of 'from
    Steve> Numeric import *'?  Using Numarray from Matplotlib would be
    Steve> useful for me because instead of learning Numerical Python
    Steve> now and later learning Numarray I would only need to learn
    Steve> Numarray.

Before you commit to just using numarray, note that the home page
warns it is an order of magnitude slower than numeric for smallish
arrays.

I will certainly support Numarray when it becomes official and
performance competitive with Numeric, if not before.  I haven't used
it yet, so don't know what will be involved.  But if I recall
correctly believe there will not be many API changes from the python
user end, so I don't think it will be difficult.  Perhaps someone has
experience with numarray and can chime in here.

If you want to be the crash test dummy and replace the 'from Numeric'
with 'from numarray' and let me know what happens, please do.  

I use matplotlib with large data arrays of EEG data (100s MB and need
to use larger), where only a small portion is on the screen at one
time.  That is why I have worked hard to make Numeric clipping
efficient in the line class.  But it still gets slow and I would like
to allow matplotlib to support memory mapped files.  I believe there
will be better support for this in numarray.  Also, I look forward to
the better indexing capabilities of numarray, which is one area where
matlab is superior.

  Eg
  matlab> ind = find(t>2);
  matlab> s(ind) = 5;

Cheers, 
John Hunter