README.md

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gnancount

Calculate the number of non-NaN elements in a strided array.

Usage

import gnancount from 'https://cdn.jsdelivr.net/gh/stdlib-js/blas-ext-base-gnancount@deno/mod.js';

The previous example will load the latest bundled code from the deno branch. Alternatively, you may load a specific version by loading the file from one of the tagged bundles. For example,

import gnancount from 'https://cdn.jsdelivr.net/gh/stdlib-js/blas-ext-base-gnancount@v0.0.0-deno/mod.js';

You can also import the following named exports from the package:

import { ndarray } from 'https://cdn.jsdelivr.net/gh/stdlib-js/blas-ext-base-gnancount@deno/mod.js';

gnancount( N, x, strideX )

Calculates the number of non-NaN elements in a strided array.

var x = [ 1.0, -2.0, NaN, 2.0 ];

var v = gnancount( x.length, x, 1 );
// returns 3

The function has the following parameters:

• N: number of indexed elements.
• x: input Array or typed array.
• strideX: stride length for x.

The N and stride parameters determine which elements in the strided array are accessed at runtime. For example, to calculate the count for every other element in x,

var x = [ 1.0, 2.0, 2.0, -7.0, -2.0, 3.0, 4.0, 2.0, NaN, NaN ];

var v = gnancount( 5, x, 2 );
// returns 4

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

import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@deno/mod.js';

var x0 = new Float64Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, NaN, NaN, 4.0 ] );
var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element

var v = gnancount( 4, x1, 2 );
// returns 3

gnancount.ndarray( N, x, strideX, offsetX )

Calculates the number of non-NaN elements in a strided array using alternative indexing semantics.

var x = [ 1.0, -2.0, NaN, 2.0 ];

var v = gnancount.ndarray( x.length, x, 1, 0 );
// returns 3

The function has the following additional parameters:

• offsetX: starting index for x.

While typed array views mandate a view offset based on the underlying buffer, the offset parameter supports indexing semantics based on a starting index. For example, to calculate the count for every other element in x starting from the second element

var x = [ 2.0, 1.0, 2.0, -2.0, -2.0, NaN, NaN, 2.0, 3.0, 4.0 ];

var v = gnancount.ndarray( 5, x, 2, 1 );
// returns 4

Notes

• If N <= 0, both functions return 0.
• Both functions support array-like objects having getter and setter accessors for array element access (e.g., @stdlib/array-base/accessor).

Examples

import uniform from 'https://cdn.jsdelivr.net/gh/stdlib-js/random-base-uniform@deno/mod.js';
import filledarrayBy from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-filled-by@deno/mod.js';
import bernoulli from 'https://cdn.jsdelivr.net/gh/stdlib-js/random-base-bernoulli@deno/mod.js';
import gnancount from 'https://cdn.jsdelivr.net/gh/stdlib-js/blas-ext-base-gnancount@deno/mod.js';

function rand() {
    if ( bernoulli( 0.8 ) < 1 ) {
        return NaN;
    }
    return uniform( -50.0, 50.0 );
}

var x = filledarrayBy( 10, 'float64', rand );
console.log( x );

var v = gnancount( x.length, x, 1 );
console.log( v );

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Notice

This package is part of stdlib, a standard library 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.