Collect only non-zero elements of a 3x3xN matrix

Hi,

I've a symbolic 3x3xN (with N variable) matrix I with some non-zero elements, like:

I(:,:,1) = 

[ 0, 0,   0]
[ 0, 0,   0]
[ 0, 0, Il1]

I(:,:,2) = 

[ 0, 0,   0]
[ 0, 0,   0]
[ 0, 0, Il2]

and I want to collect them into an array, but when I try:

[m,v]=find(I~=0)

it returns indices like m=3 v=9. How can I find them from the 3-D matrix and collect them into an array ?

Answer 1

[Image Analyst]

You simply extract them, like this:

nonZeroElements = I(I~=0);

That gives you a big long vector of all the array values that are not zero, in row major order.

[Walter Roberson]

Column major order rather than row.

Answer 2

[Matt J]

I don't have the Symbolic Math Toolbox, but you could try the NONZEROS command. Don't know if it's overloaded for type sym.

[Marco]

I tried it but it returns:

Undefined function 'nonzeros' for input arguments of type 'sym'.