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Compute the cube root of each element retrieved from an input strided array via a callback function.
npm install @stdlib/math-strided-special-cbrt-byvar cbrtBy = require( '@stdlib/math-strided-special-cbrt-by' );Computes the cube root of each element retrieved from an input strided array x via a callback function and assigns each result to an element in an output strided array y.
function accessor( v ) {
return v;
}
var x = [ 1.0, 9.0, -27.0, 81.0, -125.0 ];
var y = [ 0.0, 0.0, 0.0, 0.0, 0.0 ];
cbrtBy( x.length, x, 1, y, 1, accessor );
// y => [ 1.0, ~2.08, -3.0, ~4.327, -5.0 ]The function accepts the following arguments:
- N: number of indexed elements.
-
x: input
Array,typed array, or an array-like object (excluding strings and functions). -
strideX: index increment for
x. -
y: output
Array,typed array, or an array-like object (excluding strings and functions). -
strideY: index increment for
y. - clbk: callback function.
- thisArg: execution context (optional).
The invoked callback function is provided six arguments:
- value: input array element.
- idx: iteration index (zero-based).
-
xi: input array strided index (
offsetX + idx*strideX). -
yi: output array strided index (
offsetY + idx*strideY). - x: input array/collection.
- y: output array/collection.
To set the callback execution context, provide a thisArg.
function accessor( v ) {
this.count += 1;
return v;
}
var context = {
'count': 0
};
var x = [ 1.0, 9.0, -27.0, 81.0, -125.0 ];
var y = [ 0.0, 0.0, 0.0, 0.0, 0.0 ];
cbrtBy( x.length, x, 1, y, 1, accessor, context );
// y => [ 1.0, ~2.08, -3.0, ~4.327, -5.0 ]
var cnt = context.count;
// returns 5The N and stride parameters determine which elements in x and y 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,
function accessor( v ) {
return v;
}
var x = [ 1.0, 9.0, -27.0, 81.0, -125.0, -9.14 ];
var y = [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ];
cbrtBy( 3, x, 2, y, -1, accessor );
// y => [ -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.
var Float64Array = require( '@stdlib/array-float64' );
function accessor( v ) {
return v;
}
// Initial arrays...
var x0 = new Float64Array( [ 1.0, 9.0, -27.0, 81.0, -125.0, -9.14 ] );
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
cbrtBy( 3, x1, -2, y1, 1, accessor );
// y0 => <Float64Array>[ 0.0, 0.0, 0.0, ~-2.091, ~4.327, ~2.08 ]Computes the cube root of each element retrieved from an input strided array x via a callback function and assigns each result to an element in an output strided array y using alternative indexing semantics.
function accessor( v ) {
return v;
}
var x = [ 1.0, 9.0, -27.0, 81.0, -125.0 ];
var y = [ 0.0, 0.0, 0.0, 0.0, 0.0 ];
cbrtBy.ndarray( x.length, x, 1, 0, y, 1, 0, accessor );
// y => [ 1.0, ~2.08, -3.0, ~4.327, -5.0 ]The function accepts the following additional arguments:
-
offsetX: starting index for
x. -
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,
function accessor( v ) {
return v;
}
var x = [ 1.0, 9.0, -27.0, 81.0, -125.0, -9.14 ];
var y = [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ];
cbrtBy.ndarray( 3, x, 2, 1, y, -1, y.length-1, accessor );
// y => [ 0.0, 0.0, 0.0, ~-2.091, ~4.327, ~2.08 ]-
If a provided callback function does not return any value (or equivalently, explicitly returns
undefined), the value is ignored.function accessor() { // No-op... } var x = [ 1.0, 9.0, -27.0, 81.0, -125.0 ]; var y = [ 0.0, 0.0, 0.0, 0.0, 0.0 ]; cbrtBy( x.length, x, 1, y, 1, accessor ); // y => [ 0.0, 0.0, 0.0, 0.0, 0.0 ]
var uniform = require( '@stdlib/random-base-uniform' ).factory;
var filledarray = require( '@stdlib/array-filled' );
var filledarrayBy = require( '@stdlib/array-filled-by' );
var cbrtBy = require( '@stdlib/math-strided-special-cbrt-by' );
function accessor( v, i ) {
if ( (i%3) === 0 ) {
// Simulate a "missing" value...
return;
}
return v;
}
var x = filledarrayBy( 10, 'generic', uniform( -10.0, 10.0 ) );
console.log( x );
var y = filledarray( null, 10, 'generic' );
console.log( y );
cbrtBy.ndarray( x.length, x, 1, 0, y, -1, y.length-1, accessor );
console.log( y );-
@stdlib/math-strided/special/cbrt: compute the cube root of each element in a strided array.
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See LICENSE.
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