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Compute the principal square root for each element in a double-precision floating-point strided array.
import dsqrt from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-strided-special-dsqrt@esm/index.mjs';Computes the principal square root for each element in a double-precision floating-point strided array x and assigns the results to elements in a double-precision floating-point strided array y.
import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@esm/index.mjs';
var x = new Float64Array( [ 0.0, 4.0, 9.0, 12.0, 24.0 ] );
// Perform operation in-place:
dsqrt( x.length, x, 1, x, 1 );
// x => <Float64Array>[ 0.0, 2.0, 3.0, ~3.464, ~4.899 ]The function accepts the following arguments:
- N: number of indexed elements.
- x: input
Float64Array. - strideX: index increment for
x. - y: output
Float64Array. - strideY: index increment for
y.
The 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,
import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@esm/index.mjs';
var x = new Float64Array( [ 0.0, 4.0, 9.0, 12.0, 24.0, 64.0 ] );
var y = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
dsqrt( 3, x, 2, y, -1 );
// y => <Float64Array>[ ~4.899, 3.0, 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 Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@esm/index.mjs';
// Initial arrays...
var x0 = new Float64Array( [ 0.0, 4.0, 9.0, 12.0, 24.0, 64.0 ] );
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
dsqrt( 3, x1, -2, y1, 1 );
// y0 => <Float64Array>[ 0.0, 0.0, 0.0, 8.0, ~3.464, 2.0 ]Computes the principal square root for each element in a double-precision floating-point strided array x and assigns the results to elements in a double-precision floating-point strided array y using alternative indexing semantics.
import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@esm/index.mjs';
var x = new Float64Array( [ 0.0, 4.0, 9.0, 12.0, 24.0 ] );
var y = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0 ] );
dsqrt.ndarray( x.length, x, 1, 0, y, 1, 0 );
// y => <Float64Array>[ 0.0, 2.0, 3.0, ~3.464, ~4.899 ]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,
import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@esm/index.mjs';
var x = new Float64Array( [ 0.0, 4.0, 9.0, 12.0, 24.0, 64.0 ] );
var y = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
dsqrt.ndarray( 3, x, 2, 1, y, -1, y.length-1 );
// y => <Float64Array>[ 0.0, 0.0, 0.0, 8.0, ~3.464, 2.0 ]<!DOCTYPE html>
<html lang="en">
<body>
<script type="module">
import uniform from 'https://cdn.jsdelivr.net/gh/stdlib-js/random-base-uniform@esm/index.mjs';
import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@esm/index.mjs';
import dsqrt from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-strided-special-dsqrt@esm/index.mjs';
var x = new Float64Array( 10 );
var y = new Float64Array( 10 );
var i;
for ( i = 0; i < x.length; i++ ) {
x[ i ] = uniform( 0.0, 200.0 );
}
console.log( x );
console.log( y );
dsqrt.ndarray( x.length, x, 1, 0, y, -1, y.length-1 );
console.log( y );
</script>
</body>
</html>@stdlib/math-strided/special/dcbrt: compute the cube root of each element in a double-precision floating-point strided array.@stdlib/math-strided/special/drsqrt: compute the reciprocal square root for each element in a double-precision floating-point strided array.@stdlib/math-strided/special/sqrt: compute the principal square root for each element in a strided array.@stdlib/math-strided/special/ssqrt: compute the principal square root for each element in a single-precision floating-point strided array.
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