title: Cumulative product of matrix?
body: <p>I need to write a code to calculate cumulative product of a matrix.
  For example, if<br>
  A = ( 1  2  3 | 4  3  2 ) 
  then 
  cum.sum(A) = ( 1  2  6 | 4  24  144 ) </p>
  
  <p>Is there any good algorithm for doing this?</p>
  
  <p>I'll use R, C, Matlab or Octave. </p>