PROD Product Function

Section: Elementary Functions

Usage

Computes the product of an array along a given dimension. The general syntax for its use is 
   y = prod(x,d)

where x is an n-dimensions array of numerical type. The output is of the same numerical type as the input, except for integer types, which are automatically promoted to int32. The argument d is optional, and denotes the dimension along which to take the product. The output is computed via

If d is omitted, then the product is taken along the first non-singleton dimension of x. Note that by definition (starting with FreeMat 2.1) prod([]) = 1.

Example

The following piece of code demonstrates various uses of the product function 
--> A = [5,1,3;3,2,1;0,3,1]

A = 
 5 1 3 
 3 2 1 
 0 3 1

We start by calling prod without a dimension argument, in which case it defaults to the first nonsingular dimension (in this case, along the columns or d = 1). 

--> prod(A)

ans = 
 0 6 3

Next, we take the product along the rows. 

--> prod(A,2)

ans = 
 15 
  6 
  0