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Subject: Re: Mean of nonzero elements in a 2D Array w/o a loop?
Date: Sun, 25 Jul 2010 19:46:09 +0000 (UTC)
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"Evan " <Evan@fake.com> wrote in message <i2i3qr$lb8$1@fred.mathworks.com>...
> I can't seem to figure out how to find the mean of the non-zero elements in the rows of a 2-D array without using a for loop..
> 
> Suppose I have a 2D array
> 
> Bob = 
>          0   50   54   0
>          0   50   52   0
>          0   52   54   0
>          0   58   60   0
> 
> Is there an easy way to find the mean of each row while keeping the result a 2D array like:
> 
> Result:  52
>            51
>            53
>            59
> 
> I've tried the nonzeros command, but it keeps flattening the array before the mean command and I get the mean of the whole array rather than a row at a time.  Is there some simple way to do this without using a for loop to parse through each row at a time?
> 
> Thanks!

one of the many solutions
- for this particular case...

     m=[
          0    50    54     0
          0    50    52     0
          0    52    54     0
          0    58    60     0
     ];
     r=mean(m(:,2:3),2)
%{
%    r =
     52
     51
     53
     59
%}

us