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Return an
ndarrayelement.
To use in Observable,
at = require( 'https://cdn.jsdelivr.net/gh/stdlib-js/ndarray-at@umd/browser.js' )To vendor stdlib functionality and avoid installing dependency trees for Node.js, you can use the UMD server build:
var at = require( 'path/to/vendor/umd/ndarray-at/index.js' )To include the bundle in a webpage,
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/ndarray-at@umd/browser.js"></script>If no recognized module system is present, access bundle contents via the global scope:
<script type="text/javascript">
(function () {
window.at;
})();
</script>Returns an ndarray element.
var array = require( '@stdlib/ndarray-array' );
var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
// returns <ndarray>
var v = at( x, 0, 0 );
// returns 1
v = at( x, 0, 1 );
// returns 2
v = at( x, 1, 0 );
// returns 3
v = at( x, 1, 1 );
// returns 4The function accepts the following arguments:
- x: input
ndarray. - indices: index arguments. The number of index arguments must equal the number of dimensions.
-
If provided out-of-bounds indices, the function always returns
undefined.var array = require( '@stdlib/ndarray-array' ); var x = array( [ [ 1, 2 ], [ 3, 4 ] ] ); // returns <ndarray> var v = at( x, 10, 20 ); // returns undefined
-
Negative indices are resolved relative to the last element along the respective dimension, with the last element corresponding to
-1.var array = require( '@stdlib/ndarray-array' ); var x = array( [ [ 1, 2 ], [ 3, 4 ] ] ); // returns <ndarray> var v = at( x, -1, -1 ); // returns 4 v = at( x, -2, -2 ); // returns 1
<!DOCTYPE html>
<html lang="en">
<body>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/array-cartesian-product@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/array-zero-to@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/random-array-discrete-uniform@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/ndarray-array@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/ndarray-at@umd/browser.js"></script>
<script type="text/javascript">
(function () {
// Define a two-dimensional array:
var shape = [ 5, 5 ];
var x = array( discreteUniform( 25, -100, 100 ), {
'shape': shape
});
// Define lists of dimension indices:
var i0 = zeroTo( shape[ 0 ], 'generic' );
var i1 = zeroTo( shape[ 1 ], 'generic' );
// Create a list of index pairs:
var indices = cartesianProduct( i0, i1 );
// Print array contents...
var idx;
var i;
for ( i = 0; i < x.length; i++ ) {
idx = indices[ i ];
console.log( 'x[%d,%d] = %d', idx[ 0 ], idx[ 1 ], at( x, idx[ 0 ], idx[ 1 ] ) );
}
})();
</script>
</body>
</html>@stdlib/ndarray-array: multidimensional arrays.@stdlib/ndarray-slice: return a read-only view of an input 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.
Copyright © 2016-2025. The Stdlib Authors.
