Return the size (i.e., number of elements) of a specified dimension for a provided ndarray.
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Return the size (i.e., number of elements) of a specified dimension for a provided ndarray.
npm install @stdlib/ndarray-numel-dimension
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 numelDimension = require( '@stdlib/ndarray-numel-dimension' );
Returns the size (i.e., number of elements) of a specified dimension for a provided ndarray.
var zeros = require( '@stdlib/ndarray-zeros' );
var x = zeros( [ 4, 2, 3 ] );
// returns <ndarray>
var d = numelDimension( x, 0 );
// returns 4
The function accepts the following arguments:
-1
.@stdlib/ndarray-shape
when only a single dimension size is needed. For retrieving multiple dimension sizes, use @stdlib/ndarray/shape
directly.var zeros = require( '@stdlib/ndarray-zeros' );
var slice = require( '@stdlib/ndarray-slice' );
var E = require( '@stdlib/slice-multi' );
var S = require( '@stdlib/slice-ctor' );
var numelDimension = require( '@stdlib/ndarray-numel-dimension' );
// Create an array:
var x = zeros( [ 10, 10, 10, 10 ] );
// returns <ndarray>
// Define some slices:
var slices = [
// :,:,:,:
E( null, null, null, null ),
// 5:10,4,2:4,::-1
E( S( 5, 10 ), 4, S( 2, 4 ), S( null, null, -1 ) ),
// :,:,2,:
E( null, null, 2, null ),
// 1,2,3,:
E( 1, 2, 3, null ),
// 1,3,::2,4::2
E( 1, 3, S( null, null, 2 ), S( 4, null, 2 ) )
];
// Resolve the size of the first dimension for each slice...
var s;
var i;
for ( i = 0; i < slices.length; i++ ) {
s = slice( x, slices[ i ] );
console.log( '(%s) => %d', s.shape.join( ',' ), numelDimension( s, 0 ) );
}
@stdlib/ndarray-array
: multidimensional arrays.
@stdlib/ndarray-ctor
: multidimensional array constructor.
@stdlib/ndarray-numel
: return the number of elements in an ndarray.
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.
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