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prependSingletonDimensions

Prepend singleton dimensions.

Usage

import prependSingletonDimensions from 'https://cdn.jsdelivr.net/gh/stdlib-js/ndarray-base-prepend-singleton-dimensions@esm/index.mjs';

prependSingletonDimensions( x, n )

Returns an ndarray with a specified number of prepended singleton dimensions (i.e., dimensions whose size is equal to 1).

import array from 'https://cdn.jsdelivr.net/gh/stdlib-js/ndarray-array@esm/index.mjs';

// Create a 2x2 ndarray:
var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
// returns <ndarray>

// Prepend singleton dimensions:
var y = prependSingletonDimensions( x, 3 );
// returns <ndarray>

var sh = y.shape;
// returns [ 1, 1, 1, 2, 2 ]

Examples

<!DOCTYPE html>
<html lang="en">
<body>
<script type="module">

import array from 'https://cdn.jsdelivr.net/gh/stdlib-js/ndarray-array@esm/index.mjs';
import numel from 'https://cdn.jsdelivr.net/gh/stdlib-js/ndarray-base-numel@esm/index.mjs';
import ind2sub from 'https://cdn.jsdelivr.net/gh/stdlib-js/ndarray-ind2sub@esm/index.mjs';
import prependSingletonDimensions from 'https://cdn.jsdelivr.net/gh/stdlib-js/ndarray-base-prepend-singleton-dimensions@esm/index.mjs';

// Create a 2-dimensional array:
var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
// returns <ndarray>

// Prepend singleton dimensions:
var y = prependSingletonDimensions( x, 3 );
// returns <ndarray>

// Retrieve the shape:
var sh = y.shape;
// returns [ 1, 1, 1, 2, 2 ]

// Retrieve the number of elements:
var N = numel( sh );

// Loop through the array elements...
var i;
for ( i = 0; i < N; i++ ) {
    console.log( 'Y[%s] = %d', ind2sub( sh, i ).join( ', ' ), y.iget( i ) );
}

</script>
</body>
</html>

Notice

This package is part of stdlib, a standard library 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.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2025. The Stdlib Authors.

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