From help-octave-request at bevo dot che dot wisc dot edu  Thu Dec 16 10:41:08 1999
Subject: Re: manipulation of matrix elements
From: Mike Miller <mbmiller at taxa dot psyc dot missouri dot edu>
To: Help-Octave List <help-octave at bevo dot che dot wisc dot edu>
Date: Thu, 16 Dec 1999 10:41:06 -0600 (CST)

On Thu, 16 Dec 1999, John W. Eaton wrote:

> On 16-Dec-1999, Michael Roth <mike at aug dot ig dot erdw dot ethz dot ch> wrote:
> 
> | I tried to set a lower limit for matrix elements using the find command.
> | I think there is a bug. Have a look at the following lines:     
> | 
> | s=rand(2)
> | s =
> |   0.47926  0.89733
> |   0.77293  0.02806
> | 
> | >> [i,j]=find(s<=0.5)
> | i =
> |   1
> |   2
> | 
> | j =
> |   1
> |   2
> | 
> |                        
> | >> s(i,j)=0.5                 | In Matlab, this command gives 
> | s =                           | s =  
> |   0.50000  0.50000            |   0.50000  0.89733
> |   0.50000  0.50000            |   0.77293  0.50000
> 
> What version of Matlab does this?
> 
> If Matlab *does* behave this way, I think it is a bug in Matlab


I'm using 5.2.0.3084 under Win NT and it does *not* do what Michael Roth
reported.  It does what he attributes to octave, which is the correct
behavior, I think.

s(i,j) should take the rows from s given by the values in i, and it should
take the columns from s given by the values in j.  So, in the example
above, s(i,j) should return all .5's.

Mike

-- 
Michael B. Miller
University of Missouri--Columbia
http://taxa.psyc.missouri.edu/~mbmiller/



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