matplotlib.mlab.find() not quite like Matlab"s

Community matplotlib-users
1

I guess there is no way in Python of emulating Matlab"s

    >> detection of the number of output arguments.

    > I just got a response from c.l.p. Somebody remembered
    > seeing this at ASPN:
    > Finding out the number of values the caller is expecting « Python recipes « ActiveState Code

    > expecting() is the workhorse, equivalent to Matlab's
    > nargout:

    > import inspect,dis

Hi Darren,

Wow, I didn't know this was possible in python. Does it work under
python2.2?

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.

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?

Cheers,
JDH

2

Hi John,

    >> I guess there is no way in Python of emulating Matlab"s
    >> detection of the number of output arguments.

    > I just got a response from c.l.p. Somebody remembered
    > seeing this at ASPN:
    > Finding out the number of values the caller is expecting « Python recipes « ActiveState Code

    > expecting() is the workhorse, equivalent to Matlab's
    > nargout:

    > 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.)

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Darren