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174 changes: 174 additions & 0 deletions lib/node_modules/@stdlib/array/base/mskreject-map/README.md
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<!--

@license Apache-2.0

Copyright (c) 2024 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.

-->

# mskrejectMap

> Apply a mask to a provided input array and map the unmasked values according to a callback function.

<section class="usage">

## Usage

```javascript
var mskrejectMap = require( '@stdlib/array/base/mskreject-map' );
```

#### mskrejectMap( x, mask, clbk\[, thisArg ] )

Returns a new array by applying a mask and mapping the unmasked values according to a callback function.

```javascript
var x = [ 1, 2, 3, 4 ];

function clbk( val ) {
return val * 2;
}

var y = mskrejectMap( x, [ 0, 1, 0, 1 ], clbk );
// returns [ 2, 6 ]
```

The function supports the following parameters:

- **x**: input array.
- **mask**: mask array.
- **clbk**: function to apply.
- **thisArg**: applied function execution context (_optional_).

The `clbk` function is provided three arguments:

- **value**: current unmasked array element.
- **index**: current unmasked array element index.
- **arr**: input array.

To set the `clbk` function execution context, provide a `thisArg`.

```javascript
var x = [ 1, 2, 3, 4 ];

var mask = [ 0, 1, 0, 1 ];

var increase = 3;

function clbk( value ) {
return value + this;
}

var out = mskrejectMap( x, mask, clbk, increase );
// returns [ 4, 6 ]
```

The function **always** returns a new "generic" array.

#### mskrejectMap.assign( x, mask, out, stride, offset, clbk\[, thisArg ] )

Applies a mask to a provided input array, maps the unmasked values according to a callback function, and assigns to elements in a provided output array.

```javascript
var x = [ 1, 2, 3, 4 ];

var mask = [ 1, 0, 1, 0 ];

var out = [ 0, 0, 0, 0 ];

function clbk( val ) {
return val * 2;
}

var arr = mskrejectMap.assign( x, mask, out, -2, out.length-1, clbk );
// returns [ 0, 8, 0, 4 ]

var bool = ( arr === out );
// returns true
```

The function supports the following parameters:

- **x**: input array.
- **mask**: mask array.
- **out**: output array.
- **stride**: output array stride.
- **offset**: output array offset.
- **clbk**: function to apply.
- **thisArg**: applied function execution context (_optional_).

</section>

<!-- /.usage -->

<section class="notes">

## Notes

- If a `mask` array element is falsy, the corresponding element in `x` is **mapped** in the output array; otherwise, the corresponding element in `x` is "masked" and thus **excluded** from the output array.

</section>

<!-- /.notes -->

<section class="examples">

## Examples

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

```javascript
var zeroTo = require( '@stdlib/array/base/zero-to' );
var bernoulli = require( '@stdlib/random/array/bernoulli' );
var mskrejectMap = require( '@stdlib/array/base/mskreject-map' );

// Generate a linearly spaced array:
var x = zeroTo( 20 );
console.log( x );

// Generate a random mask:
var mask = bernoulli( x.length, 0.5, {
'dtype': 'generic'
});
console.log( mask );

function clbk( val ) {
return val * 2;
}

// Filter an array using the mask:
var y = mskrejectMap( x, mask, clbk );
console.log( y );
```

</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">

</section>

<!-- /.links -->
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/**
* @license Apache-2.0
*
* Copyright (c) 2024 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 pow = require( '@stdlib/math/base/special/pow' );
var zeroTo = require( '@stdlib/array/base/zero-to' );
var zeros = require( '@stdlib/array/zeros' );
var isArray = require( '@stdlib/assert/is-array' );
var isnan = require( '@stdlib/assert/is-nan' ).isPrimitive;
var pkg = require( './../package.json' ).name;
var mskrejectMap = require( './../lib' );


// FUNCTIONS //

/**
* Creates a benchmark function.
*
* @private
* @param {PositiveInteger} len - array length
* @returns {Function} benchmark function
*/
function createBenchmark( len ) {
var mask;
var out;
var x;

x = zeroTo( len, 'generic' );
mask = zeros( len, 'generic' );
out = zeros( len, 'generic' );

return benchmark;

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

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
v = mskrejectMap.assign( x, mask, out, 1, 0, function clbk( val ) {
return val * 2;
} );
if ( typeof v !== 'object' ) {
b.fail( 'should return an array' );
}
}
b.toc();
if ( !isArray( v ) || isnan( v[ i%len ] ) ) {
b.fail( 'should return an array' );
}
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( pkg+':assign:len='+len, f );
}
}

main();
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/**
* @license Apache-2.0
*
* Copyright (c) 2024 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 isArray = require( '@stdlib/assert/is-array' );
var zeroTo = require( '@stdlib/array/base/zero-to' );
var zeros = require( '@stdlib/array/base/zeros' );
var pkg = require( './../package.json' ).name;
var mskrejectMap = require( './../lib' );


// MAIN //

bench( pkg+'::copy:len=100', function benchmark( b ) {
var x;
var y;
var i;
var v;

x = zeroTo( 100 );
y = zeros( x.length );

b.tic();
for ( i = 0; i < b.iterations; i++ ) {
v = mskrejectMap( x, y, function clbk( val ) {
return val * 2;
} );
if ( typeof v !== 'object' ) {
b.fail( 'should return an array' );
}
}
b.toc();
if ( !isArray( v ) ) {
b.fail( 'should return an array' );
}
b.pass( 'benchmark finished' );
b.end();
});
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