Thread Subject: Passing a matrix to a function

I have two simple questions:

1. I have a matrix M(i,j). I want to create j number of
vectors V(j) each of which will have i number of entries.
For example say I have a 2 x2 matrix [1 2; 3 4]. I want to
create V(1)= (1 3), and V(2) = (2 4). How to do it?

2. How can I pass a matrix to a function? Say I have a
matrix M(i,j). I want to create a function func(M). Inside
the function I want to access the elements of matrix M.

Thank you so much in advance for your help.

"Kingshuk Majumdar":
<SNIP simplicity abound...

> I have two simple questions...

one simple answer (please, don't be offended)...

peruse this great doc:

http://www.mathworks.com/access/helpdesk/help/techdoc/learn_
matlab/bqr_2pl.html

us

> 1. I have a matrix M(i,j). I want to create j number of
> vectors V(j) each of which will have i number of entries.
> For example say I have a 2 x2 matrix [1 2; 3 4]. I want
to
> create V(1)= (1 3), and V(2) = (2 4). How to do it?

 M(:, 1) = [1; 3]; % first column

 M(:, 2) = [2; 4]; % second column

> 2. How can I pass a matrix to a function? Say I have a
> matrix M(i,j). I want to create a function func(M).
Inside
> the function I want to access the elements of matrix M.
>
> Thank you so much in advance for your help.

You can pass a matrix in the same way as any other kind of
parameter. A copy of the matrix is created if and only if
you write any element of the matrix. Therefore, the number
of matrix elements doesn't matter.

One example of a function that reads a matrix but does not
copy it:

 function func(M)

 SumOfElements = sum(M(:));

 IsZero = ~any(M(:));

 MaxElement = max(M(:));

 MinElement = min(M(:));

 end

The following function, however, does create an additional
copy of your matrix:

 function func(M)

 M(1, 1) = 0;

 end

Does this answer your questions?