FreeMat
ANY Any True Function

Section: Elementary Functions

Usage

Reduces a logical array along a given dimension by testing for any logical 1s. The general syntax for its use is

  y = any(x,d)

where x is an n-dimensions array of logical type. The output is of logical type. The argument d is optional, and denotes the dimension along which to operate. The output y is the same size as x, except that it is singular along the operated direction. So, for example, if x is a 3 x 3 x 4 array, and we any operation along dimension d=2, then the output is of size 3 x 1 x 4.

Internals

The output is computed via

\[ y(m_1,\ldots,m_{d-1},1,m_{d+1},\ldots,m_{p}) = \max_{k} x(m_1,\ldots,m_{d-1},k,m_{d+1},\ldots,m_{p}) \]

If d is omitted, then the summation is taken along the first non-singleton dimension of x.

Example

The following piece of code demonstrates various uses of the summation function

--> A = [1,0,0;1,0,0;0,0,1]

A = 
 1 0 0 
 1 0 0 
 0 0 1 

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

--> any(A)

ans = 
 1 0 1 

Next, we apply the any operation along the rows.

--> any(A,2)

ans = 
 1 
 1 
 1