Re: simple matrix problem

[Nathan Weisz]

Hi,

> The problem is, how do I detrend the 2nd column?
>
> I thought maybe the command would be
> detrend(data(1))

help -i detrend returns among other things:

 - Function File:  detrend (X, P)
     If X is a vector, `detrend (X, P)' removes the best fit of a
     polynomial of order P from the data X.

     If X is a matrix, `detrend (X, P)' does the same for each column
     in X.

     The second argument is optional.  If it is not specified, a value
     of 1 is assumed.  This corresponds to removing a linear trend.

So in your case it would probably be:
detrend(yourmatrix(:,2)); %i.e. all rows, second column
if you want to assign the result to your matrix (as second column):
yourmatrix(:,2) =  detrend(yourmatrix(:,2));

You migth consider looking at:
http://www.mathworks.com/access/helpdesk/help/techdoc/learn_matlab/ 
learn_matlab.shtml

HTH,
Nathan



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