broadcastArrays

Broadcast ndarrays to a common shape.

Usage

var broadcastArrays = require( '@stdlib/ndarray/base/broadcast-arrays' );

broadcastArrays( arrays )

Broadcasts a list of ndarrays to a common shape.

var array = require( '@stdlib/ndarray/array' );
var zeros = require( '@stdlib/ndarray/zeros' );

// Create a 2x2 ndarray:
var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
// returns <ndarray>

// Create a 2x2x2 ndarray:
var y = zeros( [ 2, 2, 2 ] );
// returns <ndarray>

// Broadcast to a common shape:
var out = broadcastArrays( [ x, y ] );
// returns [ <ndarray>, <ndarray> ]

Notes

The function throws an error if provided broadcast-incompatible ndarrays.
Returned ndarrays are views on their respective underlying data buffers. The views are typically not contiguous. As more than one element of a returned view may refer to the same memory location, writing to a view may affect multiple elements. If you need to write to a returned ndarray, copy the ndarray before performing operations which may mutate elements.
Returned ndarrays are "base" ndarrays, and, thus, the returned ndarrays do not perform bounds checking or afford any of the guarantees of the non-base ndarray constructor. The primary intent of this function is to broadcast ndarray-like objects within internal implementations and to do so with minimal overhead.
The function always returns new ndarray instances even if an input ndarray shape and the broadcasted shape are the same.

Examples

var array = require( '@stdlib/ndarray/array' );
var zeros = require( '@stdlib/ndarray/zeros' );
var numel = require( '@stdlib/ndarray/base/numel' );
var ind2sub = require( '@stdlib/ndarray/ind2sub' );
var broadcastArrays = require( '@stdlib/ndarray/base/broadcast-arrays' );

// Create a 2x2 array:
var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
// returns <ndarray>

// Create a 3x2x2 array:
var y = zeros( [ 3, 2, 2 ] );
// returns <ndarray>

// Broadcast the arrays to a common shape:
var out = broadcastArrays( [ x, y ] );
// returns [ <ndarray>, <ndarray> ]

// Retrieve the common shape:
var sh = out[ 0 ].shape;
// returns [ 3, 2, 2 ]

// Retrieve the number of elements:
var N = numel( sh );

// Loop through the array elements...
var i;
for ( i = 0; i < N; i++ ) {
    console.log( 'X[%s] = %d', ind2sub( sh, i ).join( ', ' ), out[ 0 ].iget( i ) );
}