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https://github.com/stdlib-js/strided-base-smap2

Apply a binary function accepting and returning single-precision floating-point numbers to corresponding elements in two single-precision floating-point strided input arrays and assign each result to an element in a single-precision floating-point strided output array.
https://github.com/stdlib-js/strided-base-smap2

apply array base binary float float32 flt foreach javascript map ndarray node node-js nodejs single-precision stdlib strided transform

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Apply a binary function accepting and returning single-precision floating-point numbers to corresponding elements in two single-precision floating-point strided input arrays and assign each result to an element in a single-precision floating-point strided output array.

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README 

          



  

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# smap2



[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] 



> Apply a binary function to single-precision floating-point strided input arrays and assign results to a single-precision floating-point strided output array.



## Installation



```bash

npm install @stdlib/strided-base-smap2

```



Alternatively,



-   To load the package in a website via a `script` tag without installation and bundlers, use the [ES Module][es-module] available on the [`esm`][esm-url] branch (see [README][esm-readme]).

-   If you are using Deno, visit the [`deno`][deno-url] branch (see [README][deno-readme] for usage intructions).

-   For use in Observable, or in browser/node environments, use the [Universal Module Definition (UMD)][umd] build available on the [`umd`][umd-url] branch (see [README][umd-readme]).



The [branches.md][branches-url] 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



```javascript

var smap2 = require( '@stdlib/strided-base-smap2' );

```



#### smap2( N, x, strideX, y, strideY, z, strideZ, fcn )



Applies a binary function to single-precision floating-point strided input arrays and assigns results to a single-precision floating-point strided output array.



```javascript

var Float32Array = require( '@stdlib/array-float32' );

var addf = require( '@stdlib/number-float32-base-add' );



var x = new Float32Array( [ -2.0, 1.0, 3.0, -5.0, 4.0, 0.0, -1.0, -3.0 ] );

var y = new Float32Array( [ 2.0, 1.0, 3.0, -2.0, 4.0, 1.0, -1.0, 3.0 ] );

var z = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );



smap2( x.length, x, 1, y, 1, z, 1, addf );

// z => [ 0.0, 2.0, 6.0, -7.0, 8.0, 1.0, -2.0, 0.0 ]

```



The function accepts the following arguments:



-   **N**: number of indexed elements.

-   **x**: input [`Float32Array`][@stdlib/array/float32].

-   **strideX**: index increment for `x`.

-   **y**: input [`Float32Array`][@stdlib/array/float32].

-   **strideY**: index increment for `y`.

-   **z**: output [`Float32Array`][@stdlib/array/float32].

-   **strideZ**: index increment for `z`.

-   **fcn**: function to apply.



The `N` and `stride` parameters determine which strided array elements are accessed at runtime. For example, to index every other value in `x` and to index the first `N` elements of `y` in reverse order,



```javascript

var Float32Array = require( '@stdlib/array-float32' );

var addf = require( '@stdlib/number-float32-base-add' );



var x = new Float32Array( [ -1.0, -2.0, -3.0, -4.0, -5.0, -6.0 ] );

var y = new Float32Array( [ 1.0, 1.0, 2.0, 2.0, 3.0, 3.0 ] );

var z = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );



smap2( 3, x, 2, y, -1, z, 1, addf );

// z => [ 1.0, -2.0, -4.0, 0.0, 0.0, 0.0 ]

```



Note that indexing is relative to the first index. To introduce an offset, use [`typed array`][@stdlib/array/float32] views.



```javascript

var Float32Array = require( '@stdlib/array-float32' );

var addf = require( '@stdlib/number-float32-base-add' );



// Initial arrays...

var x0 = new Float32Array( [ -1.0, -2.0, -3.0, -4.0, -5.0, -6.0 ] );

var y0 = new Float32Array( [ 1.0, 1.0, 2.0, 2.0, 3.0, 3.0 ] );

var z0 = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );



// Create offset views...

var x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element

var y1 = new Float32Array( y0.buffer, y0.BYTES_PER_ELEMENT*3 ); // start at 4th element

var z1 = new Float32Array( z0.buffer, z0.BYTES_PER_ELEMENT*2 ); // start at 3rd element



smap2( 3, x1, -2, y1, 1, z1, 1, addf );

// z0 => [ 0.0, 0.0, -4.0, -1.0, 1.0, 0.0 ]

```



#### smap2.ndarray( N, x, strideX, offsetX, y, strideY, offsetY, z, strideZ, offsetZ, fcn )



Applies a binary function to single-precision floating-point strided input arrays and assigns results to a single-precision floating-point strided output array using alternative indexing semantics.



```javascript

var Float32Array = require( '@stdlib/array-float32' );

var addf = require( '@stdlib/number-float32-base-add' );



var x = new Float32Array( [ -1.0, -2.0, -3.0, -4.0, -5.0 ] );

var y = new Float32Array( [ 1.0, 1.0, 2.0, 2.0, 3.0 ] );

var z = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 0.0 ] );



smap2.ndarray( x.length, x, 1, 0, y, 1, 0, z, 1, 0, addf );

// z => [ 0.0, -1.0, -1.0, -2.0, -2.0 ]

```



The function accepts the following addfitional arguments:



-   **offsetX**: starting index for `x`.

-   **offsetY**: starting index for `y`.

-   **offsetZ**: starting index for `z`.



While [`typed array`][@stdlib/array/float32] views mandate a view offset based on the underlying `buffer`, the offset parameters support indexing semantics based on starting indices. For example, to index every other value in `x` starting from the second value and to index the last `N` elements in `y` in reverse order,



```javascript

var Float32Array = require( '@stdlib/array-float32' );

var addf = require( '@stdlib/number-float32-base-add' );



var x = new Float32Array( [ -1.0, -2.0, -3.0, -4.0, -5.0, -6.0 ] );

var y = new Float32Array( [ 1.0, 1.0, 2.0, 2.0, 3.0, 3.0 ] );

var z = new Float32Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );



smap2.ndarray( 3, x, 2, 1, y, -1, y.length-1, z, 1, 3, addf );

// z => [ 0.0, 0.0, 0.0, 1.0, -1.0, -4.0 ]

```



## Examples



```javascript

var discreteUniform = require( '@stdlib/random-base-discrete-uniform' ).factory;

var filledarrayBy = require( '@stdlib/array-filled-by' );

var Float32Array = require( '@stdlib/array-float32' );

var addf = require( '@stdlib/number-float32-base-add' );

var smap2 = require( '@stdlib/strided-base-smap2' );



var x = filledarrayBy( 10, 'float32', discreteUniform( -100, 100 ) );

console.log( x );



var y = filledarrayBy( x.length, 'float32', discreteUniform( -100, 100 ) );

console.log( y );



var z = new Float32Array( x.length );

console.log( z );



smap2.ndarray( x.length, x, 1, 0, y, -1, y.length-1, z, 1, 0, addf );

console.log( z );

```



* * *



## C APIs



### Usage



```c

#include "stdlib/strided/base/smap2.h"

```



#### stdlib_strided_smap2( N, \*X, strideX, \*Y, strideY, \*Z, strideZ, fcn )



Applies a binary function to single-precision floating-point strided input arrays and assigns results to a single-precision floating-point strided output array.



```c

#include 



static float addf( const float x, const float y ) {

    return x + y;

}



float X[] = { 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f };

float Y[] = { 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f };

float Z[] = { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };



int64_t N = 6;



stdlib_strided_smap2( N, X, 1, Y, 1, Z, 1, addf );

```



The function accepts the following arguments:



-   **N**: `[in] int64_t` number of indexed elements.

-   **X**: `[in] float*` input array.

-   **strideX** `[in] int64_t` index increment for `X`.

-   **Y**: `[in] float*` input array.

-   **strideY**: `[in] int64_t` index increment for `Y`.

-   **Z**: `[out] float*` output array.

-   **strideZ**: `[in] int64_t` index increment for `Z`.

-   **fcn**: `[in] float (*fcn)( float, float )` binary function to apply.



```c

void stdlib_strided_smap2( const int64_t N, const float *X, const int64_t strideX, const float *Y, const int64_t strideY, float *Z, const int64_t strideZ, float (*fcn)( float, float ) );

```



### Examples



```c

#include "stdlib/strided/base/smap2.h"

#include 

#include 

#include 



// Define a callback:

static float addf( const float x, const float y ) {

    return x + y;

}



int main( void ) {

    // Create input strided arrays:

    float X[] = { 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f };

    float Y[] = { 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f };



    // Create an output strided array:

    float Z[] = { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };



    // Specify the number of elements:

    int64_t N = 6;



    // Define the strides:

    int64_t strideX = 1;

    int64_t strideY = -1;

    int64_t strideZ = 1;



    // Apply the callback:

    stdlib_strided_smap2( N, X, strideX, Y, strideY, Z, strideZ, addf );



    // Print the results:

    for ( int64_t i = 0; i < N; i++ ) {

        printf( "Z[ %"PRId64" ] = %f\n", i, Z[ i ] );

    }

}

```



* * *



## See Also



-   [`@stdlib/strided-base/dmap2`][@stdlib/strided/base/dmap2]: apply a binary function to double-precision floating-point strided input arrays and assign results to a double-precision floating-point strided output array.

-   [`@stdlib/strided-base/binary`][@stdlib/strided/base/binary]: apply a binary callback to elements in strided input arrays and assign results to elements in a strided output array.



* * *



## Notice



This package is part of [stdlib][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][stdlib], see the main project [repository][stdlib].



#### Community



[![Chat][chat-image]][chat-url]



---



## License



See [LICENSE][stdlib-license].



## Copyright



Copyright © 2016-2025. The Stdlib [Authors][stdlib-authors].



[npm-image]: http://img.shields.io/npm/v/@stdlib/strided-base-smap2.svg

[npm-url]: https://npmjs.org/package/@stdlib/strided-base-smap2



[test-image]: https://github.com/stdlib-js/strided-base-smap2/actions/workflows/test.yml/badge.svg?branch=main

[test-url]: https://github.com/stdlib-js/strided-base-smap2/actions/workflows/test.yml?query=branch:main



[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/strided-base-smap2/main.svg

[coverage-url]: https://codecov.io/github/stdlib-js/strided-base-smap2?branch=main



[chat-image]: https://img.shields.io/gitter/room/stdlib-js/stdlib.svg

[chat-url]: https://app.gitter.im/#/room/#stdlib-js_stdlib:gitter.im



[stdlib]: https://github.com/stdlib-js/stdlib



[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors



[umd]: https://github.com/umdjs/umd

[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules



[deno-url]: https://github.com/stdlib-js/strided-base-smap2/tree/deno

[deno-readme]: https://github.com/stdlib-js/strided-base-smap2/blob/deno/README.md

[umd-url]: https://github.com/stdlib-js/strided-base-smap2/tree/umd

[umd-readme]: https://github.com/stdlib-js/strided-base-smap2/blob/umd/README.md

[esm-url]: https://github.com/stdlib-js/strided-base-smap2/tree/esm

[esm-readme]: https://github.com/stdlib-js/strided-base-smap2/blob/esm/README.md

[branches-url]: https://github.com/stdlib-js/strided-base-smap2/blob/main/branches.md



[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/strided-base-smap2/main/LICENSE



[@stdlib/array/float32]: https://github.com/stdlib-js/array-float32



[@stdlib/strided/base/dmap2]: https://github.com/stdlib-js/strided-base-dmap2



[@stdlib/strided/base/binary]: https://github.com/stdlib-js/strided-base-binary