[Numpy-discussion] Matlab page on scipy wiki

Darren Dale dd55 at cornell.edu
Thu Feb 9 04:05:16 CST 2006


On Thursday 09 February 2006 3:21 am, Bill Baxter wrote:
> I added some content to the "NumPy/SciPy for Matlab users" page on the
> scipy wiki.
>
> But my knowledge of NumPy/SciPy isn't sufficient to fill in the whole chart
> of equivalents that I laid out.
> If folks who know both could browse by and maybe fill in a blank or two,
> that would be great.  I think this will be a helpful "getting started" page
> for newbies to NumPy coming from matlab, like me.  One of the most
> frustrating things is when you sit down and can't figure out how to do the
> most basic things that do in your sleep in another environment (like making
> a column vector).  So hopefully this page will help.
>
> The URL is : http://www.scipy.org/Wiki/NumPy_for_Matlab_Addicts

I filled in a couple of places, where I could. 


I have a question about upcasting related to this example:

a with elements less than 0.5 zeroed out:
Matlab: a .* (a>0.5)
NumPy: where(a<0.5, 0, a)
	
I think numpy should be able to do a*a>0.5 as well, but instead one must do: 
a*(a>0.5).astype('i')

Is it desireable to upcast bools in this case? I think so, one could always 
recover the current behavior by doing:
(a*(a>0.5)).astype('?')

Darren




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