How to get the compressed row sparse CRS in a matrix ?

I want to get the compressed row sparse (CRS) of the following matrix.

A=[ 1 0 -2 0 0;...

2 8 0 1 0;...

0 0 3 0 -2;...

0 -3 2 0 0;...

1 2 0 0 -4]

So far I have the folliwing code but how ever I do not know to get the row pointer. Hoow do I get the row pointer for the above matrix ?

So far i have...

n=length(A);

c=1;

for i=1:n

for j=1:n

if A(i,j) ~= 0;

row(c,1)=i;

col(c,1)=j;

val(c,1)=A(i,j);

index(c,1)= c;

data = {index, val};

c=c+1;

end

end

end