Re: Syntax question

[Heber Farnsworth]

When you select an element of a Matrix X you say X(r,c) where r and c 
are the row and column you want.  The colon ":" is a wildcard in this 
notation.  X(r,:) means "the rth row and every column of X" and X(:,c) 
means "every row of the cth column of X.

Heber Farnsworth

On Saturday, February 22, 2003, at 12:11 PM, Henry F. Mollet wrote:

> *Calculation of left and right eigenvector
> *belonging to largest eigenvalue of matrix,
> *then matrix/vector multiplication:
>
> [W,d] = eig(a);
> d = diag (d);
> imax = find (d==max(d));
> V = conj(inv(W));
> w1 = W(:,imax);          /line 5
> v1= real (V(imax,:)).';  /line 6
> Senmat = v1*w1''
>
> I understand everything except the ":" in lines 5 and 6. Somehow they
> instruct to pick the column vector and row vector, respectivly, which go
> with the largest eigenvalue. But how does it work?
> Henry
>
>
>
> -------------------------------------------------------------
> Octave is freely available under the terms of the GNU GPL.
>
> Octave's home on the web:  http://www.octave.org
> How to fund new projects:  http://www.octave.org/funding.html
> Subscription information:  http://www.octave.org/archive.html
> -------------------------------------------------------------



-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
-------------------------------------------------------------