About stdlib...
We 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.
The 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.
When 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.
To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!
Return an index given an index mode.
To use in Observable,
ind=require('https://cdn.jsdelivr.net/gh/stdlib-js/ndarray-base-ind@umd/browser.js')To vendor stdlib functionality and avoid installing dependency trees for Node.js, you can use the UMD server build:
varind=require('path/to/vendor/umd/ndarray-base-ind/index.js')To include the bundle in a webpage,
<scripttype="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/ndarray-base-ind@umd/browser.js"></script>If no recognized module system is present, access bundle contents via the global scope:
<scripttype="text/javascript">(function(){window.ind;})();</script>Returns an index given an index mode.
varidx=ind(2,9,'throw');// returns 2idx=ind(-1,9,'throw');// throws <RangeError>idx=ind(10,9,'throw');// throws <RangeError>// Wrapping indices around using modulo arithmetic:idx=ind(2,9,'wrap');// returns 2idx=ind(10,9,'wrap');// returns 0idx=ind(-1,9,'wrap');// returns 9// Clamping indices to first and last indices:idx=ind(2,9,'clamp');// returns 2idx=ind(10,9,'clamp');// returns 9idx=ind(-1,9,'clamp');// returns 0// Normalizing negative indices:idx=ind(2,9,'normalize');// returns 2idx=ind(-4,9,'normalize');// returns 6Returns a function for returning an index according to a provided index mode.
varfcn=ind.factory('clamp');varidx=fcn(2,9);// returns 2idx=fcn(10,9);// returns 9idx=fcn(-1,9);// returns 0The function returns a function accepts the following arguments:
- index: input index.
- max: maximum index value.
Both functions support the following modes:
- throw: specifies that the function should throw an error when an index is outside the interval
[0, max]. - normalize: specifies that the function should normalize negative indices and throw an error when an index is outside the interval
[-max-1, max]. - wrap: specifies that the function should wrap around an index using modulo arithmetic.
- clamp: specifies that the function should set an index less than
0to0(minimum index) and set an index greater thanmaxtomax.
- throw: specifies that the function should throw an error when an index is outside the interval
<!DOCTYPE html><htmllang="en"><body><scripttype="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/random-base-discrete-uniform@umd/browser.js"></script><scripttype="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/ndarray-base-ind@umd/browser.js"></script><scripttype="text/javascript">(function(){varmodes;varmode;varidx;varout;vari;modes=['clamp','wrap'];for(i=0;i<100;i++){idx=discreteUniform(-20,20);mode=modes[discreteUniform(0,modes.length-1)];out=ind(idx,9,mode);console.log('%d => %s(%d,%d) => %d',idx,mode,0,9,out);}})();</script></body></html>This package is part of 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, see the main project repository.
See LICENSE.
Copyright © 2016-2025. The Stdlib Authors.
