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About stdlib...

We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.

When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

zfill

NPM version Build Status Coverage Status

Fill a double-precision complex floating-point strided array with a specified scalar constant.

Usage

import zfill from 'https://cdn.jsdelivr.net/gh/stdlib-js/blas-ext-base-zfill@deno/mod.js';

zfill( N, alpha, x, strideX )

Fills a double-precision complex floating-point strided array x with a specified scalar constant alpha.

import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@deno/mod.js';
import Complex128Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-complex128@deno/mod.js';
import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@deno/mod.js';
import real from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-real@deno/mod.js';
import imag from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-imag@deno/mod.js';

var arr = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );
var x = new Complex128Array( arr );

var alpha = new Complex128( 10.0, 10.0 );

zfill( x.length, alpha, x, 1 );

var y = x.get( 0 );
// returns <Complex128>

var re = real( y );
// returns 10.0

var im = imag( y );
// returns 10.0

The function has the following parameters:

  • N: number of indexed elements.
  • alpha: scalar constant.
  • x: input Complex128Array.
  • strideX: index increment.

The N and stride parameters determine which elements in the strided array are accessed at runtime. For example, to fill every other element

import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@deno/mod.js';
import Complex128Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-complex128@deno/mod.js';
import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@deno/mod.js';
import real from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-real@deno/mod.js';
import imag from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-imag@deno/mod.js';

var arr = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );
var x = new Complex128Array( arr );

var alpha = new Complex128( 10.0, 10.0 );

zfill( 2, alpha, x, 2 );

var y = x.get( 0 );
// returns <Complex128>

var re = real( y );
// returns 10.0

var im = imag( y );
// returns 10.0

y = x.get( 1 );
// returns <Complex128>

re = real( y );
// returns 3.0

im = imag( y );
// returns 4.0

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 Complex128Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-complex128@deno/mod.js';
import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@deno/mod.js';
import real from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-real@deno/mod.js';
import imag from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-imag@deno/mod.js';

// Create the underlying floating-point array:
var arr = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );

// Initial array:
var x0 = new Complex128Array( arr );

// Create an offset view:
var x1 = new Complex128Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element

// Define a scalar constant:
var alpha = new Complex128( 10.0, 10.0 );

// Fill every other element:
zfill( 2, alpha, x1, 2 );

var y = x0.get( 0 );
// returns <Complex128>

var re = real( y );
// returns 1.0

var im = imag( y );
// returns 2.0

y = x0.get( 1 );
// returns <Complex128>

re = real( y );
// returns 10.0

im = imag( y );
// returns 10.0

zfill.ndarray( N, alpha, x, strideX, offsetX )

Fills a double-precision complex floating-point strided array x with a specified scalar constant alpha using alternative indexing semantics.

import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@deno/mod.js';
import Complex128Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-complex128@deno/mod.js';
import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@deno/mod.js';
import real from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-real@deno/mod.js';
import imag from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-imag@deno/mod.js';

var arr = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 ] );
var x = new Complex128Array( arr );

var alpha = new Complex128( 10.0, 10.0 );

zfill.ndarray( x.length, alpha, x, 1, 0 );

var y = x.get( 0 );
// returns <Complex128>

var re = real( y );
// returns 10.0

var im = imag( y );
// returns 10.0

The function has the following additional parameters:

  • offsetX: starting index.

While typed array views mandate a view offset based on the underlying buffer, the offset parameter supports indexing semantics based on a starting index. For example, to access only the last two elements of the strided array

import Float64Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float64@deno/mod.js';
import Complex128Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-complex128@deno/mod.js';
import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@deno/mod.js';
import real from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-real@deno/mod.js';
import imag from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-imag@deno/mod.js';

var arr = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
var x = new Complex128Array( arr );

var alpha = new Complex128( 10.0, 10.0 );

zfill.ndarray( 2, alpha, x, 1, x.length-2 );

var y = x.get( 0 );
// returns <Complex128>

var re = real( y );
// returns 1.0

var im = imag( y );
// returns 2.0

y = x.get( 1 );
// returns <Complex128>

re = real( y );
// returns 10.0

im = imag( y );
// returns 10.0

y = x.get( 2 );
// returns <Complex128>

re = real( y );
// returns 10.0

im = imag( y );
// returns 10.0

Notes

  • If N <= 0, both functions return the strided array unchanged.

Examples

import discreteUniform from 'https://cdn.jsdelivr.net/gh/stdlib-js/random-array-discrete-uniform@deno/mod.js';
import Complex128 from 'https://cdn.jsdelivr.net/gh/stdlib-js/complex-float64-ctor@deno/mod.js';
import Complex128Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-complex128@deno/mod.js';
import zfill from 'https://cdn.jsdelivr.net/gh/stdlib-js/blas-ext-base-zfill@deno/mod.js';

var xbuf = discreteUniform( 20, -100, 100, {
    'dtype': 'float64'
});
var x = new Complex128Array( xbuf.buffer );
var alpha = new Complex128( 10.0, 10.0 );

zfill( x.length, alpha, x, 1 );
console.log( x.get( 0 ).toString() );

Usage

#include "stdlib/blas/ext/base/zfill.h"

stdlib_strided_zfill( N, alpha, *X, strideX )

Fills a double-precision complex floating-point strided array X with a specified scalar constant alpha.

double x[] = { 1.0, 2.0, 3.0, 4.0 };
const stdlib_complex128_t alpha = stdlib_complex128( 2.0, 2.0 );

stdlib_strided_zfill( 2, alpha, (stdlib_complex128_t *)x, 1 );

The function accepts the following arguments:

  • N: [in] CBLAS_INT number of indexed elements.
  • alpha: [in] stdlib_complex128_t scalar constant.
  • X: [out] stdlib_complex128_t* input array.
  • strideX: [in] CBLAS_INT index increment for X.
void stdlib_strided_zfill( const CBLAS_INT N, const stdlib_complex128_t alpha, stdlib_complex128_t *X, const CBLAS_INT strideX );

stdlib_strided_zfill_ndarray( N, alpha, *X, strideX, offsetX )

Fills a double-precision complex floating-point strided array X with a specified scalar constant alpha using alternative indexing semantics.

double x[] = { 1.0, 2.0, 3.0, 4.0 };
const stdlib_complex128_t alpha = stdlib_complex128( 2.0, 2.0 );

stdlib_strided_zfill_ndarray( 4, alpha, (stdlib_complex128_t *x), 1, 0 );

The function accepts the following arguments:

  • N: [in] CBLAS_INT number of indexed elements.
  • alpha: [in] stdlib_complex128_t scalar constant.
  • X: [out] stdlib_complex128_t* input array.
  • strideX: [in] CBLAS_INT index increment for X.
  • offsetX: [in] CBLAS_INT starting index for X.
void stdlib_strided_zfill_ndarray( const CBLAS_INT N, const stdlib_complex128_t alpha, stdlib_complex128_t *X, const CBLAS_INT strideX, const CBLAS_INT offsetX );

Examples

#include "stdlib/complex/float64/ctor.h"
#include "stdlib/blas/ext/base/zfill.h"
#include <stdio.h>

int main() {
    // Create a strided array of interleaved real and imaginary components:
    double x[] = { 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 };

    // Create a scalar constant:
    const stdlib_complex128_t alpha = stdlib_complex128( 2.0, 2.0 );

    // Specify the number of elements:
    const int N = 4;

    // Specify a stride:
    const int strideX = 1;

    // Fill the array:
    stdlib_strided_zfill( N, alpha, (stdlib_complex128_t *)x, strideX );

    // Print the result:
    for ( int i = 0; i < 8; i++ ) {
        printf( "x[ %i ] = %lf\n", i, x[ i ] );
    }
}

Notice

This package is part of stdlib, a standard library 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.

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License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.