mskfilter

Apply a mask to a provided input array.

Usage

var mskfilter = require( '@stdlib/array/base/mskfilter' );

mskfilter( x, mask )

Returns a new array by applying a mask to a provided input array.

var x = [ 1, 2, 3, 4 ];

var y = mskfilter( x, [ 0, 1, 0, 1 ] );
// returns [ 2, 4 ]

The function supports the following parameters:

x: input array.
mask: mask array.

The function always returns a new "generic" array.

mskfilter.assign( x, mask, out, stride, offset )

Applies a mask to a provided input array and assigns unmasked values to elements in a provided output array.

var x = [ 1, 2, 3, 4 ];
var mask = [ 0, 1, 0, 1 ];

var out = [ 0, 0, 0, 0 ];

var arr = mskfilter.assign( x, mask, out, -2, out.length-1 );
// returns [ 0, 4, 0, 2 ]

var bool = ( arr === out );
// returns true

The function supports the following parameters:

x: input array.
mask: mask array.
out: output array.
stride: output array stride.
offset: output array offset.

Notes

If a mask array element is truthy, the corresponding element in x is included in the output array; otherwise, the corresponding element in x is "masked" and thus excluded from the output array.

Examples

var zeroTo = require( '@stdlib/array/base/zero-to' );
var bernoulli = require( '@stdlib/random/array/bernoulli' );
var mskfilter = require( '@stdlib/array/base/mskfilter' );

// Generate a linearly spaced array:
var x = zeroTo( 20 );
console.log( x );

// Generate a random mask:
var mask = bernoulli( x.length, 0.5, {
    'dtype': 'generic'
});
console.log( mask );

// Filter an array using the mask:
var y = mskfilter( x, mask );
console.log( y );