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flattenFrom

Return a copy of an input ndarray where all dimensions of the input ndarray are flattened starting from a specified dimension.

Installation

npm install @stdlib/ndarray-flatten-from

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the 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.

Usage

var flattenFrom = require( '@stdlib/ndarray-flatten-from' );

flattenFrom( x, dim[, options] )

Returns a copy of an input ndarray where all dimensions of the input ndarray are flattened starting from a specified dimension.

var array = require( '@stdlib/ndarray-array' );
var ndarray2array = require( '@stdlib/ndarray-to-array' );

var x = array( [ [ [ 1.0, 2.0 ] ], [ [ 3.0, 4.0 ] ], [ [ 5.0, 6.0 ] ] ] );
// returns <ndarray>

var y = flattenFrom( x, 1 );
// returns <ndarray>

var arr = ndarray2array( y );
// returns [ [ 1.0, 2.0 ], [ 3.0, 4.0 ], [ 5.0, 6.0 ] ]

The function accepts the following arguments:

• x: input ndarray. Must have one or more dimensions.
• dim: dimension to start flattening from. If provided an integer less than zero, the dimension index is resolved relative to the last dimension, with the last dimension corresponding to the value -1.
• options: function options (optional).

The function accepts the following options:

• order: order in which input ndarray elements should be flattened. Must be one of the following:

  • 'row-major': flatten elements in lexicographic order. For example, given a two-dimensional input ndarray (i.e., a matrix), flattening in lexicographic order means flattening the input ndarray row-by-row.
  • 'column-major': flatten elements in colexicographic order. For example, given a two-dimensional input ndarray (i.e., a matrix), flattening in colexicographic order means flattening the input ndarray column-by-column.
  • 'any': flatten according to the physical layout of the input ndarray data in memory, regardless of the stated order of the input ndarray.
  • 'same': flatten according to the stated order of the input ndarray.

  Default: 'row-major'.

• dtype: output ndarray data type. By default, the function returns an ndarray having the same data type as a provided input ndarray.

By default, the input ndarray is flattened in lexicographic order. To flatten elements in a different order, specify the order option.

var array = require( '@stdlib/ndarray-array' );
var ndarray2array = require( '@stdlib/ndarray-to-array' );

var x = array( [ [ [ 1.0, 2.0 ] ], [ [ 3.0, 4.0 ] ], [ [ 5.0, 6.0 ] ] ] );
// returns <ndarray>

var y = flattenFrom( x, 0, {
    'order': 'column-major'
});
// returns <ndarray>

var arr = ndarray2array( y );
// returns [ 1.0, 3.0, 5.0, 2.0, 4.0, 6.0 ]

By default, the output ndarray data type is inferred from the input ndarray. To return an ndarray with a different data type, specify the dtype option.

var array = require( '@stdlib/ndarray-array' );
var dtype = require( '@stdlib/ndarray-dtype' );
var ndarray2array = require( '@stdlib/ndarray-to-array' );

var x = array( [ [ [ 1.0, 2.0 ] ], [ [ 3.0, 4.0 ] ], [ [ 5.0, 6.0 ] ] ] );
// returns <ndarray>

var y = flattenFrom( x, 0, {
    'dtype': 'float32'
});
// returns <ndarray>

var dt = dtype( y );
// returns 'float32'

var arr = ndarray2array( y );
// returns [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ]

Notes

• The function always returns a copy of input ndarray data, even when an input ndarray already has the desired number of dimensions.

Examples

var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var array = require( '@stdlib/ndarray-array' );
var ndarray2array = require( '@stdlib/ndarray-to-array' );
var flattenFrom = require( '@stdlib/ndarray-flatten-from' );

var xbuf = discreteUniform( 12, -100, 100, {
    'dtype': 'generic'
});

var x = array( xbuf, {
    'shape': [ 2, 2, 3 ],
    'dtype': 'generic'
});
console.log( ndarray2array( x ) );

var y = flattenFrom( x, 1 );
console.log( ndarray2array( y ) );

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Notice

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.

Community

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License

See LICENSE.

Copyright

Copyright © 2016-2025. The Stdlib Authors.