MATLAB Central Newsreader - How to do this in the vector form?

How to do this in the vector form?

Mohammad Monfared — Wed, 21 Jan 2009 16:23:02 -0500

Hi everybody!

I have a 12 by 200 matrix, say A. I'd like to compute the mean values of each row for non-zero elements. I know some ways to to this job but not the vector form solution. Is there any vector-form answer?

thanks,
Reza.

Re: How to do this in the vector form?

Matt — Wed, 21 Jan 2009 16:37:02 -0500

"Mohammad Monfared" <gohardoust@gmail.com> wrote in message <gl7i56$pei$1@fred.mathworks.com>...
> Hi everybody!
>
> I have a 12 by 200 matrix, say A. I'd like to compute the mean values of each row for non-zero elements. I know some ways to to this job but not the vector form solution. Is there any vector-form answer?
>
> thanks,
> Reza.

sum(A,2)./sum(A~=0,2)

Re: How to do this in the vector form?

Mohammad Monfared — Wed, 21 Jan 2009 17:04:01 -0500

"Matt " <mjacobson.removethis@xorantech.com> wrote in message <gl7ive$nrj$1@fred.mathworks.com>...
> "Mohammad Monfared" <gohardoust@gmail.com> wrote in message <gl7i56$pei$1@fred.mathworks.com>...
> > Hi everybody!
> >
> > I have a 12 by 200 matrix, say A. I'd like to compute the mean values of each row for non-zero elements. I know some ways to to this job but not the vector form solution. Is there any vector-form answer?
> >
> > thanks,
> > Reza.
>
> sum(A,2)./sum(A~=0,2)
>

oh! Great and simple. so thanks!
Is it possible to use the 'trimmean' function in vector form or the 'sort' should be employed?

Reza.

Re: How to do this in the vector form?

Matt — Wed, 21 Jan 2009 17:13:02 -0500

"Mohammad Monfared" <gohardoust@gmail.com> wrote in message <gl7ki1$fhs$1@fred.mathworks.com>...
> "Matt " <mjacobson.removethis@xorantech.com> wrote in message <gl7ive$nrj$1@fred.mathworks.com>...
> > "Mohammad Monfared" <gohardoust@gmail.com> wrote in message <gl7i56$pei$1@fred.mathworks.com>...
> > > Hi everybody!
> > >
> > > I have a 12 by 200 matrix, say A. I'd like to compute the mean values of each row for non-zero elements. I know some ways to to this job but not the vector form solution. Is there any vector-form answer?
> > >
> > > thanks,
> > > Reza.
> >
> > sum(A,2)./sum(A~=0,2)
> >
>
> oh! Great and simple. so thanks!
> Is it possible to use the 'trimmean' function in vector form or the 'sort' should be employed?
>
> Reza.

I'm not familiar with 'trimmean' nor with its relation to 'sort'.

Re: How to do this in the vector form?

Walter Roberson — Wed, 21 Jan 2009 18:40:23 -0500

Matt wrote:
> "Mohammad Monfared" <gohardoust@gmail.com> wrote in message <gl7i56$pei$1@fred.mathworks.com>...

>> I have a 12 by 200 matrix, say A. I'd like to compute the mean values of each row for
>> non-zero elements.

> sum(A,2)./sum(A~=0,2)

That solution leads to unexpected results if an entire row is all-zero. On the other
hand, the original poster didn't say what should be done in that case...

--
.signature note: I am now avoiding replying to unclear or ambiguous postings.
Please review questions before posting them. Be specific. Use examples of what you mean,
of what you don't mean. Specify boundary conditions, and data classes and value
relationships -- what if we scrambled your data or used -Inf, NaN, or complex(rand,rand)?

Re: How to do this in the vector form?

Mohammad Monfared — Wed, 21 Jan 2009 19:41:02 -0500

Walter Roberson <roberson@hushmail.com> wrote in message <a_Jdl.18329$Ew6.17698@newsfe22.iad>...
> Matt wrote:
> > "Mohammad Monfared" <gohardoust@gmail.com> wrote in message <gl7i56$pei$1@fred.mathworks.com>...
>
> >> I have a 12 by 200 matrix, say A. I'd like to compute the mean values of each row for
> >> non-zero elements.
>
> > sum(A,2)./sum(A~=0,2)
>
> That solution leads to unexpected results if an entire row is all-zero. On the other
> hand, the original poster didn't say what should be done in that case...
>
> --
> .signature note: I am now avoiding replying to unclear or ambiguous postings.
> Please review questions before posting them. Be specific. Use examples of what you mean,
> of what you don't mean. Specify boundary conditions, and data classes and value
> relationships -- what if we scrambled your data or used -Inf, NaN, or complex(rand,rand)?

Yes you are right!
I was thinking a way using 'trimmean' function in a vector form. It seems I should write a function and check for occasions.