**Synopsis**Get indices where an integer array is non-zero

**Usage**`Array_Type where (Array_Type a)`

**Description**The

`where`

function examines an integer array`a`

and returns a 2-d integer array whose rows are the indices of`a`

where the corresponding element of`a`

is non-zero.**Example**Consider the following:

Here the variablevariable X = [0.0:10.0:0.01]; variable A = sin (X); variable I = where (A < 0.0); A[I] = cos (X) [I];

`X`

has been assigned an array of doubles whose elements range from`0.0`

through`10.0`

in increments of`0.01`

. The second statement assigns`A`

to an array whose elements are the`sin`

of the elements of`X`

. The third statement uses the where function to get the indices of the elements of`A`

that are less than`0.0`

. Finally, the last statement substitutes into`A`

the`cos`

of the elements of`X`

at the positions of`A`

where the corresponding`sin`

is less than`0`

. The end result is that the elements of`A`

are a mixture of sines and cosines.**See Also**`array_info, sin, cos`

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