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About stdlib...

We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

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To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

smsksqrt

NPM version Build Status Coverage Status

Compute the principal square root for each element in a single-precision floating-point strided array according to a strided mask array.

Usage

import smsksqrt from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-strided-special-smsksqrt@deno/mod.js';

smsksqrt( N, x, sx, m, sm, y, sy )

Computes the principal square root for each element in a single-precision floating-point strided array x according to a strided mask array and assigns the results to elements in a single-precision floating-point strided array y.

import Float32Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@deno/mod.js';
import Uint8Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-uint8@deno/mod.js';

var x = new Float32Array( [ 0.0, 4.0, 9.0, 12.0, 24.0 ] );
var m = new Uint8Array( [ 0, 0, 1, 0, 1 ] );
var y = new Float32Array( x.length );

smsksqrt( x.length, x, 1, m, 1, y, 1 );
// y => <Float32Array>[ 0.0, 2.0, 0.0, ~3.464, 0.0 ]

The function accepts the following arguments:

  • N: number of indexed elements.
  • x: input Float32Array.
  • sx: index increment for x.
  • m: mask Uint8Array.
  • sm: index increment for m.
  • y: output Float32Array.
  • sy: index increment for y.

The N and stride parameters determine which strided array elements are accessed at runtime. For example, to index every other value in x and to index the first N elements of y in reverse order,

import Float32Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@deno/mod.js';
import Uint8Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-uint8@deno/mod.js';

var x = new Float32Array( [ 0.0, 4.0, 9.0, 12.0, 24.0, 64.0 ] );
var m = new Uint8Array( [ 0, 0, 1, 0, 1, 1 ] );
var y = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );

smsksqrt( 3, x, 2, m, 2, y, -1 );
// y => <Float32Array>[ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ]

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

import Float32Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@deno/mod.js';
import Uint8Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-uint8@deno/mod.js';

// Initial arrays...
var x0 = new Float32Array( [ 0.0, 4.0, 9.0, 12.0, 24.0, 64.0 ] );
var m0 = new Uint8Array( [ 0, 0, 1, 0, 1, 1 ] );
var y0 = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );

// Create offset views...
var x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
var m1 = new Uint8Array( m0.buffer, m0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
var y1 = new Float32Array( y0.buffer, y0.BYTES_PER_ELEMENT*3 ); // start at 4th element

smsksqrt( 3, x1, -2, m1, -2, y1, 1 );
// y0 => <Float32Array>[ 0.0, 0.0, 0.0, 0.0, ~3.464, 2.0 ]

smsksqrt.ndarray( N, x, sx, ox, m, sm, om, y, sy, oy )

Computes the principal square root for each element in a single-precision floating-point strided array x according to a strided mask array and assigns the results to elements in a single-precision floating-point strided array y using alternative indexing semantics.

import Float32Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@deno/mod.js';
import Uint8Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-uint8@deno/mod.js';

var x = new Float32Array( [ 0.0, 4.0, 9.0, 12.0, 24.0 ] );
var m = new Uint8Array( [ 0, 0, 1, 0, 1 ] );
var y = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 0.0 ] );

smsksqrt.ndarray( x.length, x, 1, 0, m, 1, 0, y, 1, 0 );
// y => <Float32Array>[ 0.0, 2.0, 0.0, ~3.464, 0.0 ]

The function accepts the following additional arguments:

  • ox: starting index for x.
  • om: starting index for m.
  • oy: starting index for y.

While typed array views mandate a view offset based on the underlying buffer, the offset parameters support indexing semantics based on starting indices. For example, to index every other value in x starting from the second value and to index the last N elements in y,

import Float32Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@deno/mod.js';
import Uint8Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-uint8@deno/mod.js';

var x = new Float32Array( [ 0.0, 4.0, 9.0, 12.0, 24.0, 64.0 ] );
var m = new Uint8Array( [ 0, 0, 1, 0, 1, 1 ] );
var y = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );

smsksqrt.ndarray( 3, x, 2, 1, m, 2, 1, y, -1, y.length-1 );
// y => <Float32Array>[ 0.0, 0.0, 0.0, 0.0, ~3.464, 2.0 ]

Examples

import uniform from 'https://cdn.jsdelivr.net/gh/stdlib-js/random-base-uniform@deno/mod.js';
import Float32Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@deno/mod.js';
import Uint8Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-uint8@deno/mod.js';
import smsksqrt from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-strided-special-smsksqrt@deno/mod.js';

var x = new Float32Array( 10 );
var m = new Uint8Array( 10 );
var y = new Float32Array( 10 );

var i;
for ( i = 0; i < x.length; i++ ) {
    x[ i ] = uniform( 0.0, 200.0 );
    if ( uniform( 0.0, 1.0 ) < 0.5 ) {
        m[ i ] = 1;
    }
}
console.log( x );
console.log( m );
console.log( y );

smsksqrt.ndarray( x.length, x, 1, 0, m, 1, 0, y, -1, y.length-1 );
console.log( y );

See Also

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.

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License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.