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155 changes: 155 additions & 0 deletions lib/node_modules/@stdlib/blas/dscal/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.

-->

# dscal

> Multiply a double-precision floating-point vector by a scalar `alpha`.

<section class="intro">

</section>

<!-- /.intro -->

<section class="usage">

## Usage

```javascript
var dscal = require( '@stdlib/blas/dscal' );
```

#### dscal( alpha, x\[, dim] )

Multiplies a double-precision floating-point vector `x` by a scalar `alpha`.

```javascript
var Float64Array = require( '@stdlib/array/float64' );
var array = require( '@stdlib/ndarray/array' );

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

dscal( 5.0, x );

var xbuf = x.data;
// returns <Float64Array>[ 5.0, 10.0, 15.0, 20.0, 25.0 ]
```

The function has the following parameters:

- **alpha**: scalar constant.
- **x**: a non-zero-dimensional [`ndarray`][@stdlib/ndarray/ctor] whose underlying data type is `float64`. Must not be read-only.
- **dim**: dimension along which to scale vectors. Must be a negative integer. Negative indices are resolved relative to the last array dimension, with the last dimension corresponding to `-1`. Default: `-1`.

For multi-dimensional input [`ndarrays`][@stdlib/ndarray/ctor], the function performs batched computation, such that the function scales each vector in `x` according to the specified dimension index.

```javascript
var Float64Array = require( '@stdlib/array/float64' );
var array = require( '@stdlib/ndarray/array' );

var opts = {
'shape': [ 2, 3 ]
};
var x = array( new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] ), opts );

var v = x.get( 0, 0 );
// returns 1.0

dscal( 5.0, x );

v = x.get( 0, 0 );
// returns 5.0

v = x.get( 1, 2 );
// returns 30.0
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

- Negative indices are resolved relative to the last [`ndarray`][@stdlib/ndarray/ctor] dimension, with the last dimension corresponding to `-1`.
- For multi-dimensional [`ndarrays`][@stdlib/ndarray/ctor], batched computation effectively means scaling all elements of `x`; however, the choice of `dim` will significantly affect performance. For best performance, specify a `dim` which best aligns with the [memory layout][@stdlib/ndarray/orders] of provided [`ndarrays`][@stdlib/ndarray/ctor].
- `dscal()` provides a higher-level interface to the [BLAS][blas] level 1 function [`dscal`][@stdlib/blas/base/dscal].

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
var ndarray2array = require( '@stdlib/ndarray/to-array' );
var array = require( '@stdlib/ndarray/array' );
var dscal = require( '@stdlib/blas/dscal' );

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

var x = array( discreteUniform( 10, 0, 100, opts ), {
'shape': [ 5, 2 ]
});
console.log( ndarray2array( x ) );

dscal( 5.0, x );
console.log( ndarray2array( x ) );
```

</section>

<!-- /.examples -->

<!-- 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">

[blas]: http://www.netlib.org/blas

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

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

[@stdlib/blas/base/dscal]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/blas/base/dscal

<!-- <related-links> -->

<!-- </related-links> -->

</section>

<!-- /.links -->
104 changes: 104 additions & 0 deletions lib/node_modules/@stdlib/blas/dscal/benchmark/benchmark.js
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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.
*/

'use strict';

// MODULES //

var bench = require( '@stdlib/bench' );
var isnan = require( '@stdlib/math/base/assert/is-nan' );
var pow = require( '@stdlib/math/base/special/pow' );
var uniform = require( '@stdlib/random/array/uniform' );
var array = require( '@stdlib/ndarray/array' );
var format = require( '@stdlib/string/format' );
var pkg = require( './../package.json' ).name;
var dscal = require( './../lib/main.js' );


// VARIABLES //

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


// FUNCTIONS //

/**
* Creates a benchmark function.
*
* @private
* @param {PositiveInteger} len - array length
* @returns {Function} benchmark function
*/
function createBenchmark( len ) {
var x = array( uniform( len, -100.0, 100.0, opts ) );
return benchmark;

/**
* Benchmark function.
*
* @private
* @param {Benchmark} b - benchmark instance
*/
function benchmark( b ) {
var d;
var i;

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
d = dscal( 1.0, x );
if ( typeof d !== 'object' ) {
b.fail( 'should return an ndarray' );
}
}
b.toc();
if ( isnan( d.get( i%len ) ) ) {
b.fail( 'should not return NaN' );
}
b.pass( 'benchmark finished' );
b.end();
}
}


// MAIN //

/**
* Main execution sequence.
*
* @private
*/
function main() {
var len;
var min;
var max;
var f;
var i;

min = 1; // 10^min
max = 6; // 10^max

for ( i = min; i <= max; i++ ) {
len = pow( 10, i );
f = createBenchmark( len );
bench( format( '%s:len=%d', pkg, len ), f );
}
}

main();
121 changes: 121 additions & 0 deletions lib/node_modules/@stdlib/blas/dscal/benchmark/benchmark.stacks.js
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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.
*/

'use strict';

// MODULES //

var bench = require( '@stdlib/bench' );
var isnan = require( '@stdlib/math/base/assert/is-nan' );
var pow = require( '@stdlib/math/base/special/pow' );
var uniform = require( '@stdlib/random/array/uniform' );
var numel = require( '@stdlib/ndarray/base/numel' );
var array = require( '@stdlib/ndarray/array' );
var format = require( '@stdlib/string/format' );
var pkg = require( './../package.json' ).name;
var dscal = require( './../lib/main.js' );


// VARIABLES //

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


// FUNCTIONS //

/**
* Creates a benchmark function.
*
* @private
* @param {PositiveIntegerArray} shape - array shape
* @returns {Function} benchmark function
*/
function createBenchmark( shape ) {
var x;
var N;
var o;

N = numel( shape );
o = {
'shape': shape
};
x = array( uniform( N, -100.0, 100.0, OPTS ), o );

return benchmark;

/**
* Benchmark function.
*
* @private
* @param {Benchmark} b - benchmark instance
*/
function benchmark( b ) {
var d;
var i;

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
d = dscal( 1.0, x );
if ( typeof d !== 'object' ) {
b.fail( 'should return an ndarray' );
}
}
b.toc();
if ( isnan( d.iget( i%N ) ) ) {
b.fail( 'should not return NaN' );
}
b.pass( 'benchmark finished' );
b.end();
}
}


// MAIN //

/**
* Main execution sequence.
*
* @private
*/
function main() {
var shape;
var min;
var max;
var N;
var f;
var i;

min = 1; // 10^min
max = 6; // 10^max

for ( i = min; i <= max; i++ ) {
N = pow( 10, i );

shape = [ 2, N/2 ];
f = createBenchmark( shape );
bench( format( '%s::stacks:size=%d,ndims=%d,shape=(%s)', pkg, N, shape.length, shape.join( ',' ) ), f );

shape = [ N/2, 2 ];
f = createBenchmark( shape );
bench( format( '%s::stacks:size=%d,ndims=%d,shape=(%s)', pkg, N, shape.length, shape.join( ',' ) ), f );
}
}

main();
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