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330 changes: 330 additions & 0 deletions lib/node_modules/@stdlib/blas/ext/base/zlinspace/README.md
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<!--

@license Apache-2.0

Copyright (c) 2026 The Stdlib Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

-->

# zlinspace

> Fill a double-precision complex floating-point strided array with linearly spaced values over a specified interval.

<section class="usage">

## Usage

```javascript
var zlinspace = require( '@stdlib/blas/ext/base/zlinspace' );
```

#### zlinspace( N, start, stop, endpoint, x, strideX )

Fills a double-precision complex floating-point strided array with linearly spaced values over a specified interval.

```javascript
var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );

var x = new Complex128Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );

var strt = new Complex128( 0.0, 0.0 );
var stp = new Complex128( 4.0, 2.0 );

zlinspace( x.length, strt, stp, true, x, 1 );
// x => <Complex128Array>[ 0.0, 0.0, 2.0, 1.0, 4.0, 2.0 ]
```

The function has the following parameters:

- **N**: number of indexed elements.
- **start**: start of interval ([`Complex128`][@stdlib/complex/float64/ctor]).
- **stop**: end of interval ([`Complex128`][@stdlib/complex/float64/ctor]).
- **endpoint**: boolean indicating whether to include the `stop` value when writing values to the input array. If `true`, the input array is filled with evenly spaced values over the closed interval `[start, stop]`. If `false`, the input array is filled with evenly spaced values over the half-open interval `[start, stop)`.
- **x**: input [`Complex128Array`][@stdlib/array/complex128].
- **strideX**: stride length.

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

```javascript
var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );

var x = new Complex128Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );

var strt = new Complex128( 1.0, 0.0 );
var stp = new Complex128( 3.0, 2.0 );

zlinspace( 2, strt, stp, true, x, 2 );
// x => <Complex128Array>[ 1.0, 0.0, 0.0, 0.0, 3.0, 2.0, 0.0, 0.0 ]
```

#### zlinspace.ndarray( N, start, stop, endpoint, x, strideX, offsetX )

Fills a double-precision complex floating-point strided array with linearly spaced values over a specified interval using alternative indexing semantics.

```javascript
var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );

var x = new Complex128Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );

var strt = new Complex128( 0.0, 0.0 );
var stp = new Complex128( 4.0, 2.0 );

zlinspace.ndarray( x.length, strt, stp, true, x, 1, 0 );
// x => <Complex128Array>[ 0.0, 0.0, 2.0, 1.0, 4.0, 2.0 ]
```

The function has the following additional parameters:

- **offsetX**: starting index.

While [`typed array`][mdn-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 three elements:

```javascript
var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );

var x = new Complex128Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );

var strt = new Complex128( 1.0, 0.0 );
var stp = new Complex128( 3.0, 2.0 );

zlinspace.ndarray( 2, strt, stp, true, x, 1, 1 );
// x => <Complex128Array>[ 0.0, 0.0, 1.0, 0.0, 3.0, 2.0 ]
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

- The real and imaginary components are interpolated independently. Given `start = a + bi` and `stop = c + di`, the spacing for each component is

<!-- eslint-disable no-tabs -->

```text
Δ_re = (c - a) / (M - 1)
Δ_im = (d - b) / (M - 1)
```

where `M` is the number of generated values (which is either `N` or `N+1` depending on whether `endpoint` is `true` or `false`, respectively).

- When the number of generated values is greater than `1` and `endpoint` is `true`, the set of values written to a provided input array is guaranteed to include the `start` and `stop` values. Beware, however, that values between `start` and `stop` are subject to floating-point rounding errors.

- When `N = 1` and `endpoint` is `false`, only the `start` value is written to a provided input array. When `N = 1` and `endpoint` is `true`, only the `stop` value is written to a provided input array.

- If `N <= 0`, both functions return `x` unchanged.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );
var logEach = require( '@stdlib/console/log-each' );
var zlinspace = require( '@stdlib/blas/ext/base/zlinspace' );

var x = new Complex128Array( 10 );

var strt = new Complex128( 0.0, 0.0 );
var stp = new Complex128( 10.0, 5.0 );

zlinspace( x.length, strt, stp, true, x, 1 );
logEach( '%s', x );
```

</section>

<!-- /.examples -->

<!-- C interface documentation. -->

* * *

<section class="c">

## C APIs

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- C usage documentation. -->

<section class="usage">

### Usage

```c
#include "stdlib/blas/ext/base/zlinspace.h"
```

#### stdlib_strided_zlinspace( N, start, stop, endpoint, \*X, strideX )

Fills a double-precision complex floating-point strided array with linearly spaced values over a specified interval.

```c
#include "stdlib/complex/float64/ctor.h"
#include <stdbool.h>

stdlib_complex128_t start = stdlib_complex128( 0.0, 0.0 );
stdlib_complex128_t stop = stdlib_complex128( 4.0, 2.0 );

double x[] = { 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 };

stdlib_strided_zlinspace( 4, start, stop, true, (stdlib_complex128_t *)x, 1 );
```

The function accepts the following arguments:

- **N**: `[in] CBLAS_INT` number of indexed elements.
- **start**: `[in] stdlib_complex128_t` start of interval.
- **stop**: `[in] stdlib_complex128_t` end of interval.
- **endpoint**: `[in] bool` boolean indicating whether to include the `stop` value when writing values to the input array. If `true`, the input array is filled with evenly spaced values over the closed interval `[start, stop]`. If `false`, the input array is filled with evenly spaced values over the half-open interval `[start, stop)`.
- **X**: `[out] stdlib_complex128_t*` input array.
- **strideX**: `[in] CBLAS_INT` stride length.

```c
void stdlib_strided_zlinspace( const CBLAS_INT N, const stdlib_complex128_t start, const stdlib_complex128_t stop, const bool endpoint, stdlib_complex128_t *X, const CBLAS_INT strideX );
```

<!-- lint disable maximum-heading-length -->

#### stdlib_strided_zlinspace_ndarray( N, start, stop, endpoint, \*X, strideX, offsetX )

Fills a double-precision complex floating-point strided array with linearly spaced values over a specified interval using alternative indexing semantics.

```c
#include "stdlib/complex/float64/ctor.h"
#include <stdbool.h>

stdlib_complex128_t start = stdlib_complex128( 0.0, 0.0 );
stdlib_complex128_t stop = stdlib_complex128( 4.0, 2.0 );

double x[] = { 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 };

stdlib_strided_zlinspace_ndarray( 4, start, stop, true, (stdlib_complex128_t *)x, 1, 0 );
```

The function accepts the following arguments:

- **N**: `[in] CBLAS_INT` number of indexed elements.
- **start**: `[in] stdlib_complex128_t` start of interval.
- **stop**: `[in] stdlib_complex128_t` end of interval.
- **endpoint**: `[in] bool` boolean indicating whether to include the `stop` value when writing values to the input array. If `true`, the input array is filled with evenly spaced values over the closed interval `[start, stop]`. If `false`, the input array is filled with evenly spaced values over the half-open interval `[start, stop)`.
- **X**: `[out] stdlib_complex128_t*` input array.
- **strideX**: `[in] CBLAS_INT` stride length.
- **offsetX**: `[in] CBLAS_INT` starting index.

```c
void stdlib_strided_zlinspace_ndarray( const CBLAS_INT N, const stdlib_complex128_t start, const stdlib_complex128_t stop, const bool endpoint, stdlib_complex128_t *X, const CBLAS_INT strideX, const CBLAS_INT offsetX );
```

</section>

<!-- /.usage -->

<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

</section>

<!-- /.notes -->

<!-- C API usage examples. -->

<section class="examples">

### Examples

```c
#include "stdlib/blas/ext/base/zlinspace.h"
#include "stdlib/complex/float64/ctor.h"
#include "stdlib/complex/float64/real.h"
#include "stdlib/complex/float64/imag.h"
#include <stdio.h>
#include <stdbool.h>

int main( void ) {
// Create a strided array:
double x[] = { 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 };

// Specify the number of indexed elements:
const int N = 8;

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

// Create start and stop values:
const stdlib_complex128_t start = stdlib_complex128( 0.0, 0.0 );
const stdlib_complex128_t stop = stdlib_complex128( 10.0, 5.0 );

// Fill the array:
stdlib_strided_zlinspace( N, start, stop, true, (stdlib_complex128_t *)x, strideX );

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

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

[@stdlib/array/complex128]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/complex128

[@stdlib/complex/float64/ctor]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/complex/float64/ctor

[mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray

</section>

<!-- /.links -->
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