extracting rows in a matrix

[Carlo Rossi]

this is very cool but actually I need to write something that is good
for Matlab too; and I notice only now that it doens't work in Matlab

-
thanks

--- Mer 13/5/09, Ben Abbott <bpabbott at mac.com> ha scritto:

Da: Ben Abbott <bpabbott at mac.com>
Oggetto: Re: extracting rows in a matrix
A: serosole at yahoo.it
Cc: help-octave at octave.org
Data: Mercoledì 13 maggio 2009, 01:13


On May 12, 2009, at 6:03 PM, Carlo Rossi wrote:

> Hello,
>  I have a matrix A 450x10  and I need t extract randomly 1/5 of 500 rows and create with these rows another matrix B.
> Is there any function to do it? Any helps?
> 
> thanks,

You can do that in one line, but using "randperm" and Octave's cool method for indexing.

    B = A(randperm (size (A, 1)), :)(1:size (A, 1)/5, :);

Ben



      
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