{"id":25478459,"url":"https://github.com/stdlib-js/strided-base-dmap2","last_synced_at":"2025-06-30T19:03:44.956Z","repository":{"id":41355325,"uuid":"421608644","full_name":"stdlib-js/strided-base-dmap2","owner":"stdlib-js","description":"Apply a binary function accepting and returning double-precision floating-point numbers to corresponding elements in two double-precision floating-point strided input arrays and assign each result to an element in a double-precision floating-point strided output array.","archived":false,"fork":false,"pushed_at":"2025-05-19T01:11:37.000Z","size":415,"stargazers_count":2,"open_issues_count":0,"forks_count":0,"subscribers_count":3,"default_branch":"main","last_synced_at":"2025-05-19T02:24:05.681Z","etag":null,"topics":["apply","array","base","binary","dbl","double","double-precision","float64","foreach","javascript","map","ndarray","node","node-js","nodejs","stdlib","strided","transform"],"latest_commit_sha":null,"homepage":"https://github.com/stdlib-js/stdlib","language":"JavaScript","has_issues":false,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"apache-2.0","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/stdlib-js.png","metadata":{"files":{"readme":"README.md","changelog":"CHANGELOG.md","contributing":"CONTRIBUTING.md","funding":null,"license":"LICENSE","code_of_conduct":"CODE_OF_CONDUCT.md","threat_model":null,"audit":null,"citation":"CITATION.cff","codeowners":null,"security":"SECURITY.md","support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null},"funding":{"github":["stdlib-js"],"open_collective":"stdlib","tidelift":"npm/@stdlib/stdlib"}},"created_at":"2021-10-26T23:01:13.000Z","updated_at":"2025-05-19T01:06:11.000Z","dependencies_parsed_at":"2023-02-17T06:30:53.755Z","dependency_job_id":"9e6d4930-9b06-4f88-acae-071609578b3a","html_url":"https://github.com/stdlib-js/strided-base-dmap2","commit_stats":{"total_commits":40,"total_committers":1,"mean_commits":40.0,"dds":0.0,"last_synced_commit":"76be8c54f7fb8688f0c87f665b4ab8b950725e41"},"previous_names":[],"tags_count":21,"template":false,"template_full_name":null,"purl":"pkg:github/stdlib-js/strided-base-dmap2","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/stdlib-js%2Fstrided-base-dmap2","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/stdlib-js%2Fstrided-base-dmap2/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/stdlib-js%2Fstrided-base-dmap2/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/stdlib-js%2Fstrided-base-dmap2/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/stdlib-js","download_url":"https://codeload.github.com/stdlib-js/strided-base-dmap2/tar.gz/refs/heads/main","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/stdlib-js%2Fstrided-base-dmap2/sbom","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":260898203,"owners_count":23079228,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["apply","array","base","binary","dbl","double","double-precision","float64","foreach","javascript","map","ndarray","node","node-js","nodejs","stdlib","strided","transform"],"created_at":"2025-02-18T14:33:15.970Z","updated_at":"2025-06-30T19:03:44.943Z","avatar_url":"https://github.com/stdlib-js.png","language":"JavaScript","funding_links":["https://github.com/sponsors/stdlib-js","https://opencollective.com/stdlib","https://tidelift.com/funding/github/npm/@stdlib/stdlib"],"categories":[],"sub_categories":[],"readme":"\u003c!--\n\n@license Apache-2.0\n\nCopyright (c) 2021 The Stdlib Authors.\n\nLicensed under the Apache License, Version 2.0 (the \"License\");\nyou may not use this file except in compliance with the License.\nYou may obtain a copy of the License at\n\n   http://www.apache.org/licenses/LICENSE-2.0\n\nUnless required by applicable law or agreed to in writing, software\ndistributed under the License is distributed on an \"AS IS\" BASIS,\nWITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\nSee the License for the specific language governing permissions and\nlimitations under the License.\n\n--\u003e\n\n\u003c!-- lint disable maximum-heading-length --\u003e\n\n\n\u003cdetails\u003e\n  \u003csummary\u003e\n    About stdlib...\n  \u003c/summary\u003e\n  \u003cp\u003eWe 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.\u003c/p\u003e\n  \u003cp\u003eThe 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.\u003c/p\u003e\n  \u003cp\u003eWhen 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.\u003c/p\u003e\n  \u003cp\u003eTo join us in bringing numerical computing to the web, get started by checking us out on \u003ca href=\"https://github.com/stdlib-js/stdlib\"\u003eGitHub\u003c/a\u003e, and please consider \u003ca href=\"https://opencollective.com/stdlib\"\u003efinancially supporting stdlib\u003c/a\u003e. We greatly appreciate your continued support!\u003c/p\u003e\n\u003c/details\u003e\n\n# dmap2\n\n[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] \u003c!-- [![dependencies][dependencies-image]][dependencies-url] --\u003e\n\n\u003e Apply a binary function to double-precision floating-point strided input arrays and assign results to a double-precision floating-point strided output array.\n\n\u003csection class=\"intro\"\u003e\n\n\u003c/section\u003e\n\n\u003c!-- /.intro --\u003e\n\n\u003csection class=\"installation\"\u003e\n\n## Installation\n\n```bash\nnpm install @stdlib/strided-base-dmap2\n```\n\nAlternatively,\n\n-   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]).\n-   If you are using Deno, visit the [`deno`][deno-url] branch (see [README][deno-readme] for usage intructions).\n-   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]).\n\nThe [branches.md][branches-url] file summarizes the available branches and displays a diagram illustrating their relationships.\n\nTo 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.\n\n\u003c/section\u003e\n\n\u003csection class=\"usage\"\u003e\n\n## Usage\n\n```javascript\nvar dmap2 = require( '@stdlib/strided-base-dmap2' );\n```\n\n#### dmap2( N, x, strideX, y, strideY, z, strideZ, fcn )\n\nApplies a binary function to double-precision floating-point strided input arrays and assigns results to a double-precision floating-point strided output array.\n\n```javascript\nvar Float64Array = require( '@stdlib/array-float64' );\nvar add = require( '@stdlib/number-float64-base-add' );\n\nvar x = new Float64Array( [ -2.0, 1.0, 3.0, -5.0, 4.0, 0.0, -1.0, -3.0 ] );\nvar y = new Float64Array( [ 2.0, 1.0, 3.0, -2.0, 4.0, 1.0, -1.0, 3.0 ] );\nvar z = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );\n\ndmap2( x.length, x, 1, y, 1, z, 1, add );\n// z =\u003e \u003cFloat64Array\u003e[ 0.0, 2.0, 6.0, -7.0, 8.0, 1.0, -2.0, 0.0 ]\n```\n\nThe function accepts the following arguments:\n\n-   **N**: number of indexed elements.\n-   **x**: input [`Float64Array`][@stdlib/array/float64].\n-   **strideX**: index increment for `x`.\n-   **y**: input [`Float64Array`][@stdlib/array/float64].\n-   **strideY**: index increment for `y`.\n-   **z**: output [`Float64Array`][@stdlib/array/float64].\n-   **strideZ**: index increment for `z`.\n-   **fcn**: function to apply.\n\nThe `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,\n\n```javascript\nvar Float64Array = require( '@stdlib/array-float64' );\nvar add = require( '@stdlib/number-float64-base-add' );\n\nvar x = new Float64Array( [ -1.0, -2.0, -3.0, -4.0, -5.0, -6.0 ] );\nvar y = new Float64Array( [ 1.0, 1.0, 2.0, 2.0, 3.0, 3.0 ] );\nvar z = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );\n\ndmap2( 3, x, 2, y, -1, z, 1, add );\n// z =\u003e \u003cFloat64Array\u003e[ 1.0, -2.0, -4.0, 0.0, 0.0, 0.0 ]\n```\n\nNote that indexing is relative to the first index. To introduce an offset, use [`typed array`][@stdlib/array/float64] views.\n\n```javascript\nvar Float64Array = require( '@stdlib/array-float64' );\nvar add = require( '@stdlib/number-float64-base-add' );\n\n// Initial arrays...\nvar x0 = new Float64Array( [ -1.0, -2.0, -3.0, -4.0, -5.0, -6.0 ] );\nvar y0 = new Float64Array( [ 1.0, 1.0, 2.0, 2.0, 3.0, 3.0 ] );\nvar z0 = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );\n\n// Create offset views...\nvar x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element\nvar y1 = new Float64Array( y0.buffer, y0.BYTES_PER_ELEMENT*3 ); // start at 4th element\nvar z1 = new Float64Array( z0.buffer, z0.BYTES_PER_ELEMENT*2 ); // start at 3rd element\n\ndmap2( 3, x1, -2, y1, 1, z1, 1, add );\n// z0 =\u003e \u003cFloat64Array\u003e[ 0.0, 0.0, -4.0, -1.0, 1.0, 0.0 ]\n```\n\n#### dmap2.ndarray( N, x, strideX, offsetX, y, strideY, offsetY, z, strideZ, offsetZ, fcn )\n\nApplies a binary function to double-precision floating-point strided input arrays and assigns results to a double-precision floating-point strided output array using alternative indexing semantics.\n\n```javascript\nvar Float64Array = require( '@stdlib/array-float64' );\nvar add = require( '@stdlib/number-float64-base-add' );\n\nvar x = new Float64Array( [ -1.0, -2.0, -3.0, -4.0, -5.0 ] );\nvar y = new Float64Array( [ 1.0, 1.0, 2.0, 2.0, 3.0 ] );\nvar z = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0 ] );\n\ndmap2.ndarray( x.length, x, 1, 0, y, 1, 0, z, 1, 0, add );\n// z =\u003e \u003cFloat64Array\u003e[ 0.0, -1.0, -1.0, -2.0, -2.0 ]\n```\n\nThe function accepts the following additional arguments:\n\n-   **offsetX**: starting index for `x`.\n-   **offsetY**: starting index for `y`.\n-   **offsetZ**: starting index for `z`.\n\nWhile [`typed array`][@stdlib/array/float64] 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,\n\n```javascript\nvar Float64Array = require( '@stdlib/array-float64' );\nvar add = require( '@stdlib/number-float64-base-add' );\n\nvar x = new Float64Array( [ -1.0, -2.0, -3.0, -4.0, -5.0, -6.0 ] );\nvar y = new Float64Array( [ 1.0, 1.0, 2.0, 2.0, 3.0, 3.0 ] );\nvar z = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );\n\ndmap2.ndarray( 3, x, 2, 1, y, -1, y.length-1, z, 1, 3, add );\n// z =\u003e \u003cFloat64Array\u003e[ 0.0, 0.0, 0.0, 1.0, -1.0, -4.0 ]\n```\n\n\u003c/section\u003e\n\n\u003c!-- /.usage --\u003e\n\n\u003csection class=\"notes\"\u003e\n\n\u003c/section\u003e\n\n\u003c!-- /.notes --\u003e\n\n\u003csection class=\"examples\"\u003e\n\n## Examples\n\n\u003c!-- eslint no-undef: \"error\" --\u003e\n\n```javascript\nvar discreteUniform = require( '@stdlib/random-base-discrete-uniform' ).factory;\nvar filledarrayBy = require( '@stdlib/array-filled-by' );\nvar Float64Array = require( '@stdlib/array-float64' );\nvar add = require( '@stdlib/number-float64-base-add' );\nvar dmap2 = require( '@stdlib/strided-base-dmap2' );\n\nvar x = filledarrayBy( 10, 'float64', discreteUniform( -100, 100 ) );\nconsole.log( x );\n\nvar y = filledarrayBy( x.length, 'float64', discreteUniform( -100, 100 ) );\nconsole.log( y );\n\nvar z = new Float64Array( x.length );\nconsole.log( z );\n\ndmap2.ndarray( x.length, x, 1, 0, y, -1, y.length-1, z, 1, 0, add );\nconsole.log( z );\n```\n\n\u003c/section\u003e\n\n\u003c!-- /.examples --\u003e\n\n\u003c!-- C interface documentation. --\u003e\n\n* * *\n\n\u003csection class=\"c\"\u003e\n\n## C APIs\n\n\u003c!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. --\u003e\n\n\u003csection class=\"intro\"\u003e\n\n\u003c/section\u003e\n\n\u003c!-- /.intro --\u003e\n\n\u003c!-- C usage documentation. --\u003e\n\n\u003csection class=\"usage\"\u003e\n\n### Usage\n\n```c\n#include \"stdlib/strided/base/dmap2.h\"\n```\n\n#### stdlib_strided_dmap2( N, \\*X, strideX, \\*Y, strideY, \\*Z, strideZ, fcn )\n\nApplies a binary function to double-precision floating-point strided input arrays and assigns results to a double-precision floating-point strided output array.\n\n```c\n#include \u003cstdint.h\u003e\n\nstatic double add( const double x, const double y ) {\n    return x + y;\n}\n\ndouble X[] = { 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 };\ndouble Y[] = { 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 };\ndouble Z[] = { 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 };\n\nint64_t N = 6;\n\nstdlib_strided_dmap2( N, X, 1, Y, 1, Z, 1, add );\n```\n\nThe function accepts the following arguments:\n\n-   **N**: `[in] int64_t` number of indexed elements.\n-   **X**: `[in] double*` input array.\n-   **strideX** `[in] int64_t` index increment for `X`.\n-   **Y**: `[in] double*` input array.\n-   **strideY**: `[in] int64_t` index increment for `Y`.\n-   **Z**: `[out] double*` output array.\n-   **strideZ**: `[in] int64_t` index increment for `Z`.\n-   **fcn**: `[in] double (*fcn)( double, double )` binary function to apply.\n\n```c\nvoid stdlib_strided_dmap2( const int64_t N, const double *X, const int64_t strideX, const double *Y, const int64_t strideY, double *Z, const int64_t strideZ, double (*fcn)( double, double ) );\n```\n\n\u003c/section\u003e\n\n\u003c!-- /.usage --\u003e\n\n\u003c!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. --\u003e\n\n\u003csection class=\"notes\"\u003e\n\n\u003c/section\u003e\n\n\u003c!-- /.notes --\u003e\n\n\u003c!-- C API usage examples. --\u003e\n\n\u003csection class=\"examples\"\u003e\n\n### Examples\n\n```c\n#include \"stdlib/strided/base/dmap2.h\"\n#include \u003cstdint.h\u003e\n#include \u003cstdio.h\u003e\n#include \u003cinttypes.h\u003e\n\n// Define a callback:\nstatic double add( const double x, const double y ) {\n    return x + y;\n}\n\nint main( void ) {\n    // Create input strided arrays:\n    double X[] = { 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 };\n    double Y[] = { 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 };\n\n    // Create an output strided array:\n    double Z[] = { 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 };\n\n    // Specify the number of elements:\n    int64_t N = 6;\n\n    // Define the strides:\n    int64_t strideX = 1;\n    int64_t strideY = -1;\n    int64_t strideZ = 1;\n\n    // Apply the callback:\n    stdlib_strided_dmap2( N, X, strideX, Y, strideY, Z, strideZ, add );\n\n    // Print the results:\n    for ( int64_t i = 0; i \u003c N; i++ ) {\n        printf( \"Z[ %\"PRId64\" ] = %lf\\n\", i, Z[ i ] );\n    }\n}\n```\n\n\u003c/section\u003e\n\n\u003c!-- /.examples --\u003e\n\n\u003c/section\u003e\n\n\u003c!-- /.c --\u003e\n\n\u003c!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. --\u003e\n\n\u003csection class=\"related\"\u003e\n\n* * *\n\n## See Also\n\n-   \u003cspan class=\"package-name\"\u003e[`@stdlib/strided-base/smap2`][@stdlib/strided/base/smap2]\u003c/span\u003e\u003cspan class=\"delimiter\"\u003e: \u003c/span\u003e\u003cspan class=\"description\"\u003eapply a binary function to single-precision floating-point strided input arrays and assign results to a single-precision floating-point strided output array.\u003c/span\u003e\n-   \u003cspan class=\"package-name\"\u003e[`@stdlib/strided-base/binary`][@stdlib/strided/base/binary]\u003c/span\u003e\u003cspan class=\"delimiter\"\u003e: \u003c/span\u003e\u003cspan class=\"description\"\u003eapply a binary callback to elements in strided input arrays and assign results to elements in a strided output array.\u003c/span\u003e\n\n\u003c/section\u003e\n\n\u003c!-- /.related --\u003e\n\n\u003c!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. --\u003e\n\n\n\u003csection class=\"main-repo\" \u003e\n\n* * *\n\n## Notice\n\nThis 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.\n\nFor 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].\n\n#### Community\n\n[![Chat][chat-image]][chat-url]\n\n---\n\n## License\n\nSee [LICENSE][stdlib-license].\n\n\n## Copyright\n\nCopyright \u0026copy; 2016-2025. The Stdlib [Authors][stdlib-authors].\n\n\u003c/section\u003e\n\n\u003c!-- /.stdlib --\u003e\n\n\u003c!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. --\u003e\n\n\u003csection class=\"links\"\u003e\n\n[npm-image]: http://img.shields.io/npm/v/@stdlib/strided-base-dmap2.svg\n[npm-url]: https://npmjs.org/package/@stdlib/strided-base-dmap2\n\n[test-image]: https://github.com/stdlib-js/strided-base-dmap2/actions/workflows/test.yml/badge.svg?branch=main\n[test-url]: https://github.com/stdlib-js/strided-base-dmap2/actions/workflows/test.yml?query=branch:main\n\n[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/strided-base-dmap2/main.svg\n[coverage-url]: https://codecov.io/github/stdlib-js/strided-base-dmap2?branch=main\n\n\u003c!--\n\n[dependencies-image]: https://img.shields.io/david/stdlib-js/strided-base-dmap2.svg\n[dependencies-url]: https://david-dm.org/stdlib-js/strided-base-dmap2/main\n\n--\u003e\n\n[chat-image]: https://img.shields.io/gitter/room/stdlib-js/stdlib.svg\n[chat-url]: https://app.gitter.im/#/room/#stdlib-js_stdlib:gitter.im\n\n[stdlib]: https://github.com/stdlib-js/stdlib\n\n[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors\n\n[umd]: https://github.com/umdjs/umd\n[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules\n\n[deno-url]: https://github.com/stdlib-js/strided-base-dmap2/tree/deno\n[deno-readme]: https://github.com/stdlib-js/strided-base-dmap2/blob/deno/README.md\n[umd-url]: https://github.com/stdlib-js/strided-base-dmap2/tree/umd\n[umd-readme]: https://github.com/stdlib-js/strided-base-dmap2/blob/umd/README.md\n[esm-url]: https://github.com/stdlib-js/strided-base-dmap2/tree/esm\n[esm-readme]: https://github.com/stdlib-js/strided-base-dmap2/blob/esm/README.md\n[branches-url]: https://github.com/stdlib-js/strided-base-dmap2/blob/main/branches.md\n\n[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/strided-base-dmap2/main/LICENSE\n\n[@stdlib/array/float64]: https://github.com/stdlib-js/array-float64\n\n\u003c!-- \u003crelated-links\u003e --\u003e\n\n[@stdlib/strided/base/smap2]: https://github.com/stdlib-js/strided-base-smap2\n\n[@stdlib/strided/base/binary]: https://github.com/stdlib-js/strided-base-binary\n\n\u003c!-- \u003c/related-links\u003e --\u003e\n\n\u003c/section\u003e\n\n\u003c!-- /.links --\u003e\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fstdlib-js%2Fstrided-base-dmap2","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fstdlib-js%2Fstrided-base-dmap2","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fstdlib-js%2Fstrided-base-dmap2/lists"}