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scusome

Cumulatively test whether at least k elements in a single-precision floating-point strided array are truthy.

Installation

npm install @stdlib/blas-ext-base-scusome

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

Usage

var scusome = require( '@stdlib/blas-ext-base-scusome' );

scusome( N, k, x, strideX, out, strideOut )

Cumulatively tests whether at least k elements in a single-precision floating-point strided array are truthy.

var Float32Array = require( '@stdlib/array-float32' );
var BooleanArray = require( '@stdlib/array-bool' );

var x = new Float32Array( [ 0.0, 0.0, 1.0, 1.0, 1.0 ] );
var out = new BooleanArray( 5 );

scusome( x.length, 2, x, 1, out, 1 );
// out => <BooleanArray>[ false, false, false, true, true ]

The function has the following parameters:

• N: number of indexed elements.
• k: minimum number of truthy elements.
• x: input Float32Array.
• strideX: stride length for x.
• out: output BooleanArray.
• strideOut: stride length for out.

The N and stride parameters determine which elements in the strided arrays are accessed at runtime. For example, to cumulatively test every other element:

var Float32Array = require( '@stdlib/array-float32' );
var BooleanArray = require( '@stdlib/array-bool' );

var x = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0 ] );
var out = new BooleanArray( 4 );

scusome( 4, 2, x, 2, out, 1 );
// out => <BooleanArray>[ false, false, false, true ]

Note that indexing is relative to the first index. To introduce an offset, use typed array views.

var Float32Array = require( '@stdlib/array-float32' );
var BooleanArray = require( '@stdlib/array-bool' );

// Initial arrays...
var x0 = new Float32Array( [ 0.0, 0.0, 0.0, 1.0, 1.0, 1.0 ] );
var o0 = new BooleanArray( x0.length );

// Create offset views...
var x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
var o1 = new BooleanArray( o0.buffer, o0.BYTES_PER_ELEMENT*3 ); // start at 4th element

scusome( 3, 2, x1, 2, o1, 1 );
// o0 => <BooleanArray>[ false, false, false, false, false, true ]

scusome.ndarray( N, k, x, strideX, offsetX, out, strideOut, offsetOut )

Cumulatively tests whether at least k elements in a single-precision floating-point strided array are truthy using alternative indexing semantics.

var Float32Array = require( '@stdlib/array-float32' );
var BooleanArray = require( '@stdlib/array-bool' );

var x = new Float32Array( [ 0.0, 0.0, 1.0, 1.0, 1.0 ] );
var out = new BooleanArray( 5 );

scusome.ndarray( x.length, 2, x, 1, 0, out, 1, 0 );
// out => <BooleanArray>[ false, false, false, true, true ]

The function has the following additional parameters:

• offsetX: starting index for x.
• offsetOut: starting index for out.

While typed array views mandate a view offset based on the underlying buffer, offset parameters support indexing semantics based on starting indices. For example, to cumulatively test every other element starting from the third element:

var Float32Array = require( '@stdlib/array-float32' );
var BooleanArray = require( '@stdlib/array-bool' );

var x = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0 ] );
var out = new BooleanArray( 3 );

scusome.ndarray( 3, 1, x, 2, 2, out, 1, 0 );
// out => <BooleanArray>[ false, true, true ]

Notes

• If N <= 0, both functions return out unchanged.
• Both functions explicitly treat NaN values as falsy.

Examples

var bernoulli = require( '@stdlib/random-array-bernoulli' );
var BooleanArray = require( '@stdlib/array-bool' );
var logEach = require( '@stdlib/console-log-each' );
var scusome = require( '@stdlib/blas-ext-base-scusome' );

var x = bernoulli( 10, 0.5, {
    'dtype': 'float32'
});
console.log( x );

var out = new BooleanArray( x.length );
scusome( x.length, 5, x, 1, out, 1 );
logEach( '%s', out );

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C APIs

Usage

#include "stdlib/blas/ext/base/scusome.h"

stdlib_strided_scusome( N, k, *X, strideX, *Out, strideOut )

Cumulatively tests whether at least k elements in a single-precision floating-point strided array are truthy.

#include <stdbool.h>

const float x[] = { 0.0f, 0.0f, 1.0f, 1.0f, 1.0f };
bool out[] = { false, false, false, false, false };

stdlib_strided_scusome( 5, 2, x, 1, out, 1 );

The function accepts the following arguments:

• N: [in] CBLAS_INT number of indexed elements.
• k: [in] CBLAS_INT minimum number of truthy elements.
• X: [in] float* input array.
• strideX: [in] CBLAS_INT stride length for X.
• Out: [out] bool* output array.
• strideOut: [in] CBLAS_INT stride length for Out.

void stdlib_strided_scusome( const CBLAS_INT N, const CBLAS_INT k, const float *X, const CBLAS_INT strideX, bool *Out, const CBLAS_INT strideOut );

stdlib_strided_scusome_ndarray( N, k, *X, strideX, offsetX, *Out, strideOut, offsetOut )

Cumulatively tests whether at least k elements in a single-precision floating-point strided array are truthy using alternative indexing semantics.

#include <stdbool.h>

const float x[] = { 0.0f, 0.0f, 1.0f, 1.0f, 1.0f };
bool out[] = { false, false, false, false, false };

stdlib_strided_scusome_ndarray( 5, 2, x, 1, 0, out, 1, 0 );

The function accepts the following arguments:

• N: [in] CBLAS_INT number of indexed elements.
• k: [in] CBLAS_INT minimum number of truthy elements.
• X: [in] float* input array.
• strideX: [in] CBLAS_INT stride length for X.
• offsetX: [in] CBLAS_INT starting index for X.
• Out: [out] bool* output array.
• strideOut: [in] CBLAS_INT stride length for Out.
• offsetOut: [in] CBLAS_INT starting index for Out.

void stdlib_strided_scusome_ndarray( const CBLAS_INT N, const CBLAS_INT k, const float *X, const CBLAS_INT strideX, const CBLAS_INT offsetX, bool *Out, const CBLAS_INT strideOut, const CBLAS_INT offsetOut );

Notes

• Both functions explicitly treat NaN values as falsy.

Examples

#include "stdlib/blas/ext/base/scusome.h"
#include <stdio.h>
#include <stdbool.h>

int main( void ) {
    // Create strided arrays:
    const float x[] = { 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f };
    bool out[] = { false, false, false, false, false, false, false, false };

    // Specify the number of indexed elements:
    const int N = 8;

    // Specify the minimum number of truthy elements:
    const int k = 2;

    // Specify strides:
    const int strideX = 1;
    const int strideOut = 1;

    // Cumulatively test whether at least `k` elements are truthy:
    stdlib_strided_scusome( N, k, x, strideX, out, strideOut );

    // Print the results:
    for ( int i = 0; i < 8; i++ ) {
        printf( "Out[ %i ] = %s\n", i, out[ i ] ? "true" : "false" );
    }
}

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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

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License

See LICENSE.

Copyright

Copyright © 2016-2026. The Stdlib Authors.