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Apply a unary callback to elements in a strided input array and assign results to elements in a strided output array.
import unary from 'https://cdn.jsdelivr.net/gh/stdlib-js/strided-base-unary@deno/mod.js';You can also import the following named exports from the package:
import { ndarray } from 'https://cdn.jsdelivr.net/gh/stdlib-js/strided-base-unary@deno/mod.js';Applies a unary callback to elements in a strided input array and assigns results to elements in a strided output array.
import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@deno/mod.js';
import abs from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-abs@deno/mod.js';
var x = new Float64Array( [ -2.0, 1.0, 3.0, -5.0, 4.0, 0.0, -1.0, -3.0 ] );
// Compute the absolute values in-place:
unary( [ x, x ], [ x.length ], [ 1, 1 ], abs );
// x => <Float64Array>[ 2.0, 1.0, 3.0, 5.0, 4.0, 0.0, 1.0, 3.0 ]The function accepts the following arguments:
- arrays: array-like object containing one strided input array and one strided output array.
- shape: array-like object containing a single element, the number of indexed elements.
- strides: array-like object containing the stride lengths for the strided input and output arrays.
- fcn: unary function to apply.
The shape and strides parameters determine which elements in the strided input and output arrays are accessed at runtime. For example, to index every other value in the strided input array and to index the first N elements of the strided output array in reverse order,
import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@deno/mod.js';
import abs from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-abs@deno/mod.js';
var x = new Float64Array( [ -1.0, -2.0, -3.0, -4.0, -5.0, -6.0 ] );
var y = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
var N = 3;
unary( [ x, y ], [ N ], [ 2, -1 ], abs );
// y => <Float64Array>[ 5.0, 3.0, 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.
import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@deno/mod.js';
import abs from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-abs@deno/mod.js';
// Initial arrays...
var x0 = new Float64Array( [ -1.0, -2.0, -3.0, -4.0, -5.0, -6.0 ] );
var y0 = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
// Create offset views...
var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
var y1 = new Float64Array( y0.buffer, y0.BYTES_PER_ELEMENT*3 ); // start at 4th element
var N = 3;
unary( [ x1, y1 ], [ N ], [ -2, 1 ], abs );
// y0 => <Float64Array>[ 0.0, 0.0, 0.0, 6.0, 4.0, 2.0 ]Applies a unary callback to elements in a strided input array and assigns results to elements in a strided output array using alternative indexing semantics.
import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@deno/mod.js';
import abs from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-abs@deno/mod.js';
var x = new Float64Array( [ -1.0, -2.0, -3.0, -4.0, -5.0 ] );
var y = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0 ] );
unary.ndarray( [ x, y ], [ x.length ], [ 1, 1 ], [ 0, 0 ], abs );
// y => <Float64Array>[ 1.0, 2.0, 3.0, 4.0, 5.0 ]The function accepts the following additional arguments:
- offsets: array-like object containing the starting indices (i.e., index offsets) for the strided input and output arrays.
While typed array views mandate a view offset based on the underlying buffer, the offsets parameter supports indexing semantics based on starting indices. For example, to index every other value in the strided input array starting from the second value and to index the last N elements in the strided output array,
import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@deno/mod.js';
import abs from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-abs@deno/mod.js';
var x = new Float64Array( [ -1.0, -2.0, -3.0, -4.0, -5.0, -6.0 ] );
var y = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
var N = 3;
unary.ndarray( [ x, y ], [ N ], [ 2, -1 ], [ 1, y.length-1 ], abs );
// y => <Float64Array>[ 0.0, 0.0, 0.0, 6.0, 4.0, 2.0 ]var discreteUniform = require( 'https://cdn.jsdelivr.net/gh/stdlib-js/random-base-discrete-uniform' ).factory;
import filledarray from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-filled@deno/mod.js';
import filledarrayBy from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-filled-by@deno/mod.js';
import unary from 'https://cdn.jsdelivr.net/gh/stdlib-js/strided-base-unary@deno/mod.js';
function add10( x ) {
return x + 10;
}
var N = 10;
var x = filledarrayBy( N, 'generic', discreteUniform( -100, 100 ) );
console.log( x );
var y = filledarray( 0.0, N, 'generic' );
console.log( y );
var shape = [ N ];
var strides = [ 1, -1 ];
var offsets = [ 0, N-1 ];
unary.ndarray( [ x, y ], shape, strides, offsets, add10 );
console.log( y );@stdlib/strided-base/unary: apply a unary callback to elements in a strided input array and assign results to elements in a strided output array.@stdlib/strided-base/dmap: apply a unary function to a double-precision floating-point strided input array and assign results to a double-precision floating-point strided output array.@stdlib/strided-base/nullary: apply a nullary callback and assign results to elements in a strided output array.@stdlib/strided-base/quaternary: apply a quaternary callback to strided input array elements and assign results to elements in a strided output array.@stdlib/strided-base/quinary: apply a quinary callback to strided input array elements 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/ternary: apply a ternary callback to strided input array elements and assign results to elements in a strided output array.
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