Return a list of reduced dimensions in an un-normalized multi-slice.
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> Return a list of reduced dimensions in an un-normalized [MultiSlice][@stdlib/slice/multi] object.
In a multi-axis indexing expression (e.g., '1,:,2,:,0:10:1'), a non-reduced dimension corresponds to a dimension which is retained in the slice result. Only integer indexing expressions (e.g., only the first and third dimensions in '1,:,2,:,0:10:1') result in dimension reduction; slices always retain respective dimensions, even if a slice is empty or only selects a single element.
``bash`
npm install @stdlib/slice-base-reduced-dimensions
`javascript`
var reducedDimensions = require( '@stdlib/slice-base-reduced-dimensions' );
#### reducedDimensions( slice )
Returns a list of reduced dimensions in an un-normalized [MultiSlice][@stdlib/slice/multi] object.
`javascript
var MultiSlice = require( '@stdlib/slice-multi' );
var Slice = require( '@stdlib/slice-ctor' );
var s = new MultiSlice( 1, null, 2, void 0, new Slice( 0, 10, 1 ) );
// returns
var indices = reducedDimensions( s );
// returns [ 0, 2 ]
`
`javascript
var S = require( '@stdlib/slice-ctor' );
var MultiSlice = require( '@stdlib/slice-multi' );
var reducedDimensions = require( '@stdlib/slice-base-reduced-dimensions' );
var s = new MultiSlice( null, S(), -1 );
var out = reducedDimensions( s );
console.log( '%s => [%s]', s.toString(), out.join( ',' ) );
s = new MultiSlice( null );
out = reducedDimensions( s );
console.log( '%s => [%s]', s.toString(), out.join( ',' ) );
s = new MultiSlice( S( -1, null, -1 ), 3 );
out = reducedDimensions( s );
console.log( '%s => [%s]', s.toString(), out.join( ',' ) );
s = new MultiSlice( 2, S( -10, -2, 2 ), 3, null );
out = reducedDimensions( s );
console.log( '%s => [%s]', s.toString(), out.join( ',' ) );
s = new MultiSlice( S( 1, 20, 2 ), S( null, null, -1 ) );
out = reducedDimensions( s );
console.log( '%s => [%s]', s.toString(), out.join( ',' ) );
`
*
- [@stdlib/slice-base/length][@stdlib/slice/base/length]: compute the number of elements in a normalized slice.
- [@stdlib/slice-base/nonreduced-dimensions][@stdlib/slice/base/nonreduced-dimensions]: return a list of non-reduced dimensions in an un-normalized multi-slice.
- [@stdlib/slice-base/shape][@stdlib/slice/base/shape]: compute the shape of a normalized multi-slice.
*
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].
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---
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