Return an index given an index mode.
APACHE-2.0 License
Return an index given an index mode.
npm install @stdlib/ndarray-base-ind
Alternatively,
script
tag without installation and bundlers, use the ES Module available on the esm
branch (see README).deno
branch (see README for usage intructions).umd
branch (see README).The branches.md 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.
var ind = require( '@stdlib/ndarray-base-ind' );
Returns an index given an index mode
.
var idx = ind( 2, 9, 'throw' );
// returns 2
idx = 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 2
idx = ind( 10, 9, 'wrap' );
// returns 0
idx = ind( -1, 9, 'wrap' );
// returns 9
// Clamping indices to first and last indices:
idx = ind( 2, 9, 'clamp' );
// returns 2
idx = ind( 10, 9, 'clamp' );
// returns 9
idx = ind( -1, 9, 'clamp' );
// returns 0
// Normalizing negative indices:
idx = ind( 2, 9, 'normalize' );
// returns 2
idx = ind( -4, 9, 'normalize' );
// returns 6
Returns a function for returning an index according to a provided index mode
.
var fcn = ind.factory( 'clamp' );
var idx = fcn( 2, 9 );
// returns 2
idx = fcn( 10, 9 );
// returns 9
idx = fcn( -1, 9 );
// returns 0
The function returns a function accepts the following arguments:
Both functions support the following modes:
[0, max]
.[-max-1, max]
.0
to 0
(minimum index) and set an index greater than max
to max
.var discreteUniform = require( '@stdlib/random-base-discrete-uniform' );
var ind = require( '@stdlib/ndarray-base-ind' );
var modes;
var mode;
var idx;
var out;
var i;
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 );
}
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 © 2016-2024. The Stdlib Authors.