some

Test whether at least n elements along one or more ndarray dimensions are truthy.

Installation

npm install @stdlib/ndarray-some

Usage

var some = require( '@stdlib/ndarray-some' );

some( x, n[, options] )

Tests whether at least n elements along one or more ndarray dimensions are truthy.

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

// Create an input ndarray:
var x = array( [ [ [ 1.0, 0.0 ] ], [ [ 3.0, 4.0 ] ], [ [ 0.0, 6.0 ] ] ] );
// returns <ndarray>

// Perform reduction:
var out = some( x, 3 );
// returns <ndarray>[ true ]

The function accepts the following arguments:

• x: input ndarray.
• n: number of elements which must be truthy. May be either a scalar or an ndarray. Must be broadcast-compatible with the non-reduced dimensions of input ndarray. Must have an integer data type.
• options: function options (optional).

The function accepts the following options:

• dims: list of dimensions over which to perform a reduction.
• keepdims: boolean indicating whether the reduced dimensions should be included in the returned ndarray as singleton dimensions. Default: false.

By default, the function performs a reduction over all elements in a provided ndarray. To reduce specific dimensions, set the dims option.

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

// Create an input ndarray:
var x = array( [ [ [ 1.0, 0.0 ] ], [ [ 3.0, 4.0 ] ], [ [ 0.0, 6.0 ] ] ] );
// returns <ndarray>

var opts = {
    'dims': [ 0, 1 ]
};

// Perform reduction:
var out = some( x, 2, opts );
// returns <ndarray>[ true, true ]

By default, the function returns an ndarray having a shape matching only the non-reduced dimensions of the input ndarray (i.e., the reduced dimensions are dropped). To include the reduced dimensions as singleton dimensions in the output ndarray, set the keepdims option to true.

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

// Create an input ndarray:
var x = array( [ [ [ 1.0, 0.0 ] ], [ [ 3.0, 4.0 ] ], [ [ 0.0, 6.0 ] ] ] );
// returns <ndarray>

var opts = {
    'dims': [ 0, 1 ],
    'keepdims': true
};

// Perform reduction:
var out = some( x, 2, opts );
// returns <ndarray>[ [ [ true, true ] ] ]

some.assign( x, n, out[, options] )

Tests whether at least n elements along one or more ndarray dimensions are truthy and assigns the results to an output ndarray.

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

// Create an input ndarray:
var x = array( [ [ [ 1.0, 0.0 ] ], [ [ 3.0, 4.0 ] ], [ [ 0.0, 6.0 ] ] ] );
// returns <ndarray>

// Create an output ndarray:
var y = empty( [], {
    'dtype': 'bool'
});

// Perform reduction:
var out = some.assign( x, 3, y );
// returns <ndarray>[ true ]

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

The function accepts the following arguments:

• x: input ndarray.
• n: number of elements which must be truthy. May be either a scalar or an ndarray. Must be broadcast-compatible with the non-reduced dimensions of input ndarray. Must have an integer data type.
• out: output ndarray. The output ndarray must have a shape matching the non-reduced dimensions of the input ndarray.
• options: function options (optional).

The function accepts the following options:

• dims: list of dimensions over which to perform a reduction.

By default, the function performs a reduction over all elements in a provided ndarray. To reduce specific dimensions, set the dims option.

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

// Create an input ndarray:
var x = array( [ [ [ 1.0, 0.0 ] ], [ [ 3.0, 4.0 ] ], [ [ 0.0, 6.0 ] ] ] );
// returns <ndarray>

// Create an output ndarray:
var y = empty( [ 2 ], {
    'dtype': 'bool'
});

var opts = {
    'dims': [ 0, 1 ]
};

// Perform reduction:
var out = some.assign( x, 2, y, opts );
// returns <ndarray>[ true, true ]

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

Examples

var discreteUniform = require( '@stdlib/random-base-discrete-uniform' ).factory;
var ndarray2array = require( '@stdlib/ndarray-to-array' );
var scalar2ndarray = require( '@stdlib/ndarray-from-scalar' );
var fillBy = require( '@stdlib/ndarray-fill-by' );
var zeros = require( '@stdlib/ndarray-zeros' );
var some = require( '@stdlib/ndarray-some' );

var x = zeros( [ 2, 4, 5 ], {
    'dtype': 'float64'
});
x = fillBy( x, discreteUniform( 0, 10 ) );
console.log( ndarray2array( x ) );

var n = scalar2ndarray( 4, {
    'dtype': 'int8'
});
var y = some( x, n );
console.log( y.get() );

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2026. The Stdlib Authors.