cusomeBy

Cumulatively test whether at least n array elements in a provided array pass a test implemented by a predicate function.

Usage

var cusomeBy = require( '@stdlib/array/base/cusome-by' );

cusomeBy( x, n, predicate[, thisArg ] )

Cumulatively tests whether at least n array elements in a provided array pass a test implemented by a predicate function.

function fcn( value) {
    return ( value > 0 );
}

var x = [ 0, 0, 0, 1, 1 ];

var y = cusomeBy( x, 2, fcn );
// returns [ false, false, false , false, true ]

The invoked predicate function is provided three arguments:

value: collection element.
index: collection index.
collection: input collection.

To set the function execution context, provide a thisArg.

function fcn( v ) {
    this.count += 1;
    return ( v > 0 );
}

var x = [ 0, 0, 0, 1, 1 ];

var context = {
    'count': 0
};

var bool = cusomeBy( x, 1, fcn, context );
// returns [ false, false, false, true, true ]

var count = context.count;
// returns 4

cusomeBy.assign( x, n, out, stride, offset, predicate[, thisArg ] )

Cumulatively tests whether at least n array elements in a provided array pass a test implemented by a predicate function and assigns the results to a provided output array.

function fcn( v ) {
    return ( v > 0 );
}

var x = [ 0, 0, 0, 1, 1 ];
var y = [ false, null, false, null, false, null, false, null, false, null ];

var out = cusomeBy.assign( x, 2, y, 2, 0, fcn );
// returns [ false, null, false, null, false, null, false, null, true, null ]

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

Examples

var bernoulli = require( '@stdlib/random/array/bernoulli' );
var cusomeBy = require( '@stdlib/array/base/cusome-by' );

function fcn( value ) {
    return ( value > 0 );
}

// Create an array of random values:
var x = bernoulli( 10, 0.8 );
console.log( x );

// Cumulatively test whether at least three array elements are positive:
var y = cusomeBy( x, 3, fcn );
console.log( y );