Replacing specified elements of a matrix with elements of a vector

Imagine a 6X6 zero matrix Z=zeros(6,6). I have a vector v=[1 2 3 4] and I want to send the elements of this vector to specified positions of of Z. The row and column positions are given by the array IJ=[2 1; 2,4; 3 5; 6,2].

IJ =

     2     1
     2     4
     3     5
     6     2

where the left column is the row numbers and the right column shows the column numbers. The result should look like this:

     Z =

     0     0     0     0     0     0
     0     1     0     2     0     0
     0     0     0     0     3     0
     0     0     0     0     0     0
     0     0     0     0     0     0
     0     4     0     0     0     0

Answer 1

[Matt J]

[m,n]=size(Z);

Z=Z+sparse(IJ(:,1), IJ(:,2), v,m,n)

or

Z=Z+accumarray(IJ,v(:),[m,n],[],[],1)

[Saeid]

Thanks Matt!