Re: [Matplotlib-users] Re: matplotlib.mlab.find() not quite like Matlab"s

[Darren D. <dd...@co...>]

Hi John,

>     >> I guess there is no way in Python of emulating Matlab"s
>     >> detection of the number of output arguments.
>
>     Darren> I just got a response from c.l.p. Somebody remembered
>     Darren> seeing this at ASPN:
>     Darren> http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/284742
>
>     Darren> expecting() is the workhorse, equivalent to Matlab's
>     Darren> nargout:
>
>     Darren> import inspect,dis
>
> Hi Darren,
>
> Wow, I didn't know this was possible in python.  Does it work under
> python2.2?

The ASPN page says it has been tested on 2.3.3. I dont have a 2.2 installation 
handy to check it.

>
> Perhaps you would like to write up nargin and nargout function with
> some doc strings and send them my way?  I could add them to the matlab
> interface.  But we need to make sure they are 2.2 compliant.

I will give it a shot in my free time, but without getting into it, my next 
month is pretty full.

>
> As an aside, do we need nargout to make "find" work like matlab's?
> Isn't it enough just to check the shape of the input array and
> processing it one way for 1D arrays and another way for 2D arrays?
>

The problem is that mlab.find() is currently a thin wrapper around a numeric 
or numarray method, which only works for 1D arrays. ravelling the arrays 
passed to find would make it easy to continue using the method called by 
find(), but I had trouble figuring out how to process the 1xM results of that 
method back into an NxM or MxN array that could be used to index an N-D 
array.  

It would be nice to be able to address Numeric and numarray with a single 
index. Matlab does this. For example, if a=array([[1,2],[3,4]]), a[0] would 
be 1, a[1] would be 3 (Matlab's convention, again if memory serves.) 

-- 

Darren