Simultaneously sort two strided arrays based on the sort order of the first array using heapsort.
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Simultaneously sort two strided arrays based on the sort order of the first array using heapsort.
bash
npm install @stdlib/blas-ext-base-gsort2hpscript tag without installation and bundlers, use the [ES Module][es-module] available on the [esm][esm-url] branch (see [README][esm-readme]).deno][deno-url] branch (see [README][deno-readme] for usage intructions).umd][umd-url] branch (see [README][umd-readme]).javascript
var gsort2hp = require( '@stdlib/blas-ext-base-gsort2hp' );javascript
var x = [ 1.0, -2.0, 3.0, -4.0 ];
var y = [ 0.0, 1.0, 2.0, 3.0 ];
gsort2hp( x.length, 1.0, x, 1, y, 1 );
console.log( x );
// => [ -4.0, -2.0, 1.0, 3.0 ]
console.log( y );
// => [ 3.0, 1.0, 0.0, 2.0 ]order < 0.0, the input strided array x is sorted in decreasing order. If order > 0.0, the input strided array x is sorted in increasing order. If order == 0.0, the input strided arrays are left unchanged.Array][mdn-array] or [typed array][mdn-typed-array].x.Array][mdn-array] or [typed array][mdn-typed-array].y.N and stride parameters determine which elements in the strided arrays are accessed at runtime. For example, to sort every other element:javascript
var x = [ 1.0, -2.0, 3.0, -4.0 ];
var y = [ 0.0, 1.0, 2.0, 3.0 ];
gsort2hp( 2, -1.0, x, 2, y, 2 );
console.log( x );
// => [ 3.0, -2.0, 1.0, -4.0 ]
console.log( y );
// => [ 2.0, 1.0, 0.0, 3.0 ]typed array][mdn-typed-array] views.javascript
var Float64Array = require( '@stdlib/array-float64' );
// Initial arrays...
var x0 = new Float64Array( [ 1.0, 2.0, 3.0, 4.0 ] );
var y0 = new Float64Array( [ 0.0, 1.0, 2.0, 3.0 ] );
// 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*1 ); // start at 2nd element
// Sort every other element...
gsort2hp( 2, -1.0, x1, 2, y1, 2 );
console.log( x0 );
// => <Float64Array>[ 1.0, 4.0, 3.0, 2.0 ]
console.log( y0 );
// => <Float64Array>[ 0.0, 3.0, 2.0, 1.0 ]javascript
var x = [ 1.0, -2.0, 3.0, -4.0 ];
var y = [ 0.0, 1.0, 2.0, 3.0 ];
gsort2hp.ndarray( x.length, 1.0, x, 1, 0, y, 1, 0 );
console.log( x );
// => [ -4.0, -2.0, 1.0, 3.0 ]
console.log( y );
// => [ 3.0, 1.0, 0.0, 2.0 ]x.y.typed array][mdn-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 access only the last three elements:javascript
var x = [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ];
var y = [ 0.0, 1.0, 2.0, 3.0, 4.0, 5.0 ];
gsort2hp.ndarray( 3, 1.0, x, 1, x.length-3, y, 1, y.length-3 );
console.log( x );
// => [ 1.0, -2.0, 3.0, -6.0, -4.0, 5.0 ]
console.log( y );
// => [ 0.0, 1.0, 2.0, 5.0, 3.0, 4.0 ]N <= 0 or order == 0.0, both functions leave x and y unchanged.@stdlib/array-base/accessor][@stdlib/array/base/accessor])-0 and +0. When sorted in increasing order, -0 is sorted before +0. When sorted in decreasing order, -0 is sorted after +0.NaN values to the end. When sorted in increasing order, NaN values are sorted last. When sorted in decreasing order, NaN values are sorted first.O(1) and worst case time complexity O(N^2).N <= 20) and is particularly efficient for sorting strided arrays which are already substantially sorted.O(1) and time complexity O(N log2 N).NaN values).dsort2hp][@stdlib/blas/ext/base/dsort2hp], [ssort2hp][@stdlib/blas/ext/base/ssort2hp], etc.) are likely to be significantly more performant.javascript
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var gsort2hp = require( '@stdlib/blas-ext-base-gsort2hp' );
var x = discreteUniform( 10, -100, 100, {
'dtype': 'float64'
});
var y = discreteUniform( 10, -100, 100, {
'dtype': 'float64'
});
console.log( x );
console.log( y );
gsort2hp( x.length, -1.0, x, -1, y, -1 );
console.log( x );
console.log( y );
