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zwxsa

Subtract a scalar constant from each element in an input one-dimensional double-precision complex floating-point ndarray and assign the results to elements in a one-dimensional double-precision complex floating-point output ndarray.

Installation

npm install @stdlib/blas-ext-base-ndarray-zwxsa

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

Usage

var zwxsa = require( '@stdlib/blas-ext-base-ndarray-zwxsa' );

zwxsa( arrays )

Subtracts a scalar constant from each element in an input one-dimensional double-precision complex floating-point ndarray and assigns the results to elements in a one-dimensional double-precision complex floating-point output ndarray.

var Complex128Vector = require( '@stdlib/ndarray-vector-complex128' );
var Complex128 = require( '@stdlib/complex-float64-ctor' );
var scalar2ndarray = require( '@stdlib/ndarray-from-scalar' );

var x = new Complex128Vector( [ -2.0, 1.0, 3.0, -5.0, 4.0, 0.0, -1.0, -3.0 ] );
var w = new Complex128Vector( 4 );

var alpha = scalar2ndarray( new Complex128( 5.0, 0.0 ), {
    'dtype': 'complex128'
});

zwxsa( [ x, w, alpha ] );
// w => <ndarray>[ <Complex128>[ -7.0, 1.0 ], <Complex128>[ -2.0, -5.0 ], <Complex128>[ -1.0, 0.0 ], <Complex128>[ -6.0, -3.0 ] ]

The function has the following parameters:

• arrays: array-like object containing the following ndarrays:

  • a one-dimensional input ndarray.
  • a one-dimensional output ndarray.
  • a zero-dimensional ndarray containing the scalar constant to subtract.

Examples

var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var Complex128Vector = require( '@stdlib/ndarray-vector-complex128' );
var Complex128 = require( '@stdlib/complex-float64-ctor' );
var scalar2ndarray = require( '@stdlib/ndarray-from-scalar' );
var ndarraylike2scalar = require( '@stdlib/ndarray-ndarraylike2scalar' );
var ndarray2array = require( '@stdlib/ndarray-to-array' );
var zwxsa = require( '@stdlib/blas-ext-base-ndarray-zwxsa' );

var opts = {
    'dtype': 'float64'
};

var x = new Complex128Vector( discreteUniform( 20, -100, 100, opts ) );
console.log( ndarray2array( x ) );

var w = new Complex128Vector( 10 );
console.log( ndarray2array( w ) );

var alpha = scalar2ndarray( new Complex128( 5.0, -3.0 ), {
    'dtype': 'complex128'
});
console.log( 'Alpha:', ndarraylike2scalar( alpha ) );

zwxsa( [ x, w, alpha ] );
console.log( ndarray2array( w ) );

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C APIs

Usage

#include "stdlib/blas/ext/base/ndarray/zwxsa.h"

stdlib_blas_ext_zwxsa( arrays )

Subtracts a scalar constant from each element in an input one-dimensional double-precision complex floating-point ndarray and assigns the results to elements in a one-dimensional double-precision complex floating-point output ndarray.

#include "stdlib/complex/float64/ctor.h"
#include "stdlib/ndarray/ctor.h"
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/base/bytes_per_element.h"
#include <stdint.h>

// Create ndarrays:
const double dataX[] = { -2.0, 1.0, 3.0, -5.0 };
double dataW[] = { 0.0, 0.0, 0.0, 0.0 };
int64_t shape[] = { 2 };
int64_t strides[] = { STDLIB_NDARRAY_COMPLEX128_BYTES_PER_ELEMENT };
int8_t submodes[] = { STDLIB_NDARRAY_INDEX_ERROR };

struct ndarray *x = stdlib_ndarray_allocate( STDLIB_NDARRAY_COMPLEX128, (uint8_t *)dataX, 1, shape, strides, 0, STDLIB_NDARRAY_ROW_MAJOR, STDLIB_NDARRAY_INDEX_ERROR, 1, submodes );
struct ndarray *w = stdlib_ndarray_allocate( STDLIB_NDARRAY_COMPLEX128, (uint8_t *)dataW, 1, shape, strides, 0, STDLIB_NDARRAY_ROW_MAJOR, STDLIB_NDARRAY_INDEX_ERROR, 1, submodes );

// Create an ndarray containing the scalar constant to subtract:
const double adata[] = { 5.0, 0.0 };
int64_t astrides[] = { 0 };

struct ndarray *alpha = stdlib_ndarray_allocate( STDLIB_NDARRAY_COMPLEX128, (uint8_t *)adata, 0, NULL, astrides, 0, STDLIB_NDARRAY_ROW_MAJOR, STDLIB_NDARRAY_INDEX_ERROR, 1, submodes );

// Perform computation:
const struct ndarray *arrays[] = { x, w, alpha };
stdlib_blas_ext_zwxsa( arrays );

// Free allocated memory:
stdlib_ndarray_free( x );
stdlib_ndarray_free( w );
stdlib_ndarray_free( alpha );

The function accepts the following arguments:

• arrays: [in] struct ndarray** list containing the following ndarrays:

  • [in] struct ndarray* a one-dimensional input ndarray.
  • [out] struct ndarray* a one-dimensional output ndarray.
  • [in] struct ndarray* a zero-dimensional ndarray containing the scalar constant to subtract.

void stdlib_blas_ext_zwxsa( const struct ndarray *arrays[] );

Examples

#include "stdlib/blas/ext/base/ndarray/zwxsa.h"
#include "stdlib/complex/float64/ctor.h"
#include "stdlib/complex/float64/real.h"
#include "stdlib/complex/float64/imag.h"
#include "stdlib/ndarray/ctor.h"
#include "stdlib/ndarray/dtypes.h"
#include "stdlib/ndarray/index_modes.h"
#include "stdlib/ndarray/orders.h"
#include "stdlib/ndarray/base/bytes_per_element.h"
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>

int main( void ) {
    // Create data buffers:
    const double dataX[] = { -2.0, 1.0, 3.0, -5.0 };
    double dataW[] = { 0.0, 0.0, 0.0, 0.0 };

    // Specify the number of array dimensions:
    const int64_t ndims = 1;

    // Specify the array shape:
    int64_t shape[] = { 2 };

    // Specify the array strides:
    int64_t strides[] = { STDLIB_NDARRAY_COMPLEX128_BYTES_PER_ELEMENT };

    // Specify the byte offset:
    const int64_t offset = 0;

    // Specify the array order:
    const enum STDLIB_NDARRAY_ORDER order = STDLIB_NDARRAY_ROW_MAJOR;

    // Specify the index mode:
    const enum STDLIB_NDARRAY_INDEX_MODE imode = STDLIB_NDARRAY_INDEX_ERROR;

    // Specify the subscript index modes:
    int8_t submodes[] = { STDLIB_NDARRAY_INDEX_ERROR };
    const int64_t nsubmodes = 1;

    // Create ndarrays:
    struct ndarray *x = stdlib_ndarray_allocate( STDLIB_NDARRAY_COMPLEX128, (uint8_t *)dataX, ndims, shape, strides, offset, order, imode, nsubmodes, submodes );

    struct ndarray *w = stdlib_ndarray_allocate( STDLIB_NDARRAY_COMPLEX128, (uint8_t *)dataW, ndims, shape, strides, offset, order, imode, nsubmodes, submodes );

    // Create a data buffer for an ndarray containing the scalar constant to subtract:
    const double adata[] = { 5.0, 0.0 };

    // Specify the array strides for a zero-dimensional ndarray:
    int64_t astrides[] = { 0 };

    // Create an ndarray containing the scalar constant to subtract:
    struct ndarray *alpha = stdlib_ndarray_allocate( STDLIB_NDARRAY_COMPLEX128, (uint8_t *)adata, 0, NULL, astrides, 0, order, imode, nsubmodes, submodes );
    if ( x == NULL || w == NULL || alpha == NULL ) {
        fprintf( stderr, "Error allocating memory.\n" );
        exit( 1 );
    }

    // Define a list of ndarrays:
    const struct ndarray *arrays[] = { x, w, alpha };

    // Perform computation:
    stdlib_blas_ext_zwxsa( arrays );

    // Print the result:
    const stdlib_complex128_t *v = (const stdlib_complex128_t *)dataW;
    for ( int i = 0; i < 2; i++ ) {
        printf( "w[ %i ] = %lf + %lfi\n", i, stdlib_complex128_real( v[ i ] ), stdlib_complex128_imag( v[ i ] ) );
    }

    // Free allocated memory:
    stdlib_ndarray_free( x );
    stdlib_ndarray_free( w );
    stdlib_ndarray_free( alpha );
}

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Notice

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.

Community

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License

See LICENSE.

Copyright

Copyright © 2016-2026. The Stdlib Authors.