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Apply a unary function to a single-precision floating-point strided input array according to a strided mask array and assign results to a single-precision floating-point strided output array.
To use in Observable,
smskmap = require( 'https://cdn.jsdelivr.net/gh/stdlib-js/strided-base-smskmap@umd/browser.js' )To vendor stdlib functionality and avoid installing dependency trees for Node.js, you can use the UMD server build:
var smskmap = require( 'path/to/vendor/umd/strided-base-smskmap/index.js' )To include the bundle in a webpage,
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/strided-base-smskmap@umd/browser.js"></script>If no recognized module system is present, access bundle contents via the global scope:
<script type="text/javascript">
(function () {
window.smskmap;
})();
</script>Applies a unary function to a single-precision floating-point strided input array according to a strided mask array and assigns results to a single-precision floating-point strided output array.
var Float32Array = require( '@stdlib/array-float32' );
var Uint8Array = require( '@stdlib/array-uint8' );
var absf = require( '@stdlib/math-base-special-absf' );
var x = new Float32Array( [ -2.0, 1.0, -3.0, -5.0, 4.0, 0.0, -1.0, -3.0 ] );
var m = new Uint8Array( [ 0, 0, 1, 0, 0, 1, 1, 0 ] );
// Compute the absolute values in-place:
smskmap( x.length, x, 1, m, 1, x, 1, absf );
// x => <Float32Array>[ 2.0, 1.0, -3.0, 5.0, 4.0, 0.0, -1.0, 3.0 ]The function accepts the following arguments:
- N: number of indexed elements.
- x: input
Float32Array. - strideX: index increment for
x. - mask: mask
Uint8Array. - strideMask: index increment for
mask. - y: output
Float32Array. - strideY: index increment for
y. - fcn: function to apply.
The N and stride parameters determine which elements in the strided arrays 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,
var Float32Array = require( '@stdlib/array-float32' );
var Uint8Array = require( '@stdlib/array-uint8' );
var absf = require( '@stdlib/math-base-special-absf' );
var x = new Float32Array( [ -1.0, -2.0, -3.0, -4.0, -5.0, -6.0 ] );
var m = new Uint8Array( [ 0, 0, 1, 0, 0, 1 ] );
var y = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
smskmap( 3, x, 2, m, 2, y, -1, absf );
// y => <Float32Array>[ 5.0, 0.0, 1.0, 0.0, 0.0, 0.0 ]Note that indexing is relative to the first index. To introduce an offset, use typed array views.
var Float32Array = require( '@stdlib/array-float32' );
var Uint8Array = require( '@stdlib/array-uint8' );
var absf = require( '@stdlib/math-base-special-absf' );
// Initial arrays...
var x0 = new Float32Array( [ -1.0, -2.0, -3.0, -4.0, -5.0, -6.0 ] );
var m0 = new Uint8Array( [ 0, 0, 1, 0, 0, 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*3 ); // start at 4th element
var y1 = new Float32Array( y0.buffer, y0.BYTES_PER_ELEMENT*3 ); // start at 4th element
smskmap( 3, x1, -2, m1, 1, y1, 1, absf );
// y0 => <Float32Array>[ 0.0, 0.0, 0.0, 6.0, 4.0, 0.0 ]Applies a unary function to a single-precision floating-point strided input array according to a strided mask array and assigns results to a single-precision floating-point strided output array using alternative indexing semantics.
var Float32Array = require( '@stdlib/array-float32' );
var Uint8Array = require( '@stdlib/array-uint8' );
var absf = require( '@stdlib/math-base-special-absf' );
var x = new Float32Array( [ -1.0, -2.0, -3.0, -4.0, -5.0 ] );
var m = new Uint8Array( [ 0, 0, 1, 0, 0 ] );
var y = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 0.0 ] );
smskmap.ndarray( x.length, x, 1, 0, m, 1, 0, y, 1, 0, absf );
// y => <Float32Array>[ 1.0, 2.0, 0.0, 4.0, 5.0 ]The function accepts the following additional arguments:
- offsetX: starting index for
x. - offsetMask: starting index for
mask. - offsetY: starting index for
y.
While typed array views mandate a view offset based on the underlying buffer, the offsetX and offsetY 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 in reverse order,
var Float32Array = require( '@stdlib/array-float32' );
var Uint8Array = require( '@stdlib/array-uint8' );
var absf = require( '@stdlib/math-base-special-absf' );
var x = new Float32Array( [ -1.0, -2.0, -3.0, -4.0, -5.0, -6.0 ] );
var m = new Uint8Array( [ 0, 0, 1, 0, 0, 1 ] );
var y = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
smskmap.ndarray( 3, x, 2, 1, m, 2, 1, y, -1, y.length-1, absf );
// y => <Float32Array>[ 0.0, 0.0, 0.0, 0.0, 4.0, 2.0 ]<!DOCTYPE html>
<html lang="en">
<body>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-round@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/random-base-randu@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/random-base-bernoulli@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/array-uint8@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/strided-base-smskmap@umd/browser.js"></script>
<script type="text/javascript">
(function () {
function scale( x ) {
return x * 10.0;
}
var x = new Float32Array( 10 );
var m = new Uint8Array( x.length );
var y = new Float32Array( x.length );
var i;
for ( i = 0; i < x.length; i++ ) {
x[ i ] = round( (randu()*200.0) - 100.0 );
m[ i ] = bernoulli( 0.2 );
}
console.log( x );
console.log( m );
console.log( y );
smskmap.ndarray( x.length, x, 1, 0, m, 1, 0, y, -1, y.length-1, scale );
console.log( y );
})();
</script>
</body>
</html>@stdlib/strided-base/dmskmap: apply a unary function to a double-precision floating-point strided input array according to a strided mask array and assign results to a double-precision floating-point strided output array.@stdlib/strided-base/mskunary: apply a unary callback to elements in a strided input array according to elements in a strided mask array and assign results to elements in a strided output array.@stdlib/strided-base/smap: apply a unary function to a single-precision floating-point strided input array and assign results to a single-precision floating-point strided output array.@stdlib/strided-base/smskmap2: apply a binary function to single-precision floating-point strided input arrays according to a strided mask array and assign results to a single-precision floating-point strided output array.
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.
See LICENSE.
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