where

The C++ interface for where. More...

array	where (const array &input)
	Indices where nonzero (zero-based indexing). More...
void	where (array &row, array &column, const array &input)
	row and column indices of nonzero elements in input More...

Detailed Description

The C++ interface for where.

Returns the indicies of the non-zero values in an set of elements.

These functions can also be used with conditions as parameters. In such a case, the input array to the function is a boolean array.

Function Documentation

array af::where

(

const array &

input

)

Indices where nonzero (zero-based indexing).

array a = randu(20e6);
array ind = where(a > .5);

array b = a(ind); // pull out non-zero elements
array c = a(a > .5); // implicitly uses where()

Parameters

[in]

input

Returns

[out] indices of nonzero elements

void af::where	(	array &	row,
		array &	column,
		const array &	input
	)

row and column indices of nonzero elements in input

array a = randu(1000,1000);
array row, col;
where(row, col, a > .5);

array b = a(row,col); // pull out nonzero elements

Parameters

[in]	input
[out]	row
[out]	column