flatten4d

Flatten a four-dimensional nested array.

Usage

var flatten4d = require( '@stdlib/array/base/flatten4d' );

flatten4d( x, shape, colexicographic )

Flattens a four-dimensional nested array.

var x = [ [ [ [ 1, 2 ] ] ], [ [ [ 3, 4 ] ] ] ];

var out = flatten4d( x, [ 2, 1, 1, 2 ], false );
// returns [ 1, 2, 3, 4 ]

To flatten in colexicographic order, provide a third argument equal to true.

var x = [ [ [ [ 1, 2 ] ] ], [ [ [ 3, 4 ] ] ] ];

var out = flatten4d( x, [ 2, 1, 1, 2 ], true );
// returns [ 1, 3, 2, 4 ]

flatten4d.assign( x, shape, colexicographic, out, stride, offset )

Flattens a four-dimensional nested array and assigns elements to a provided output array.

var Float64Array = require( '@stdlib/array/float64' );

var x = [ [ [ [ 1, 2 ] ] ], [ [ [ 3, 4 ] ] ] ];
var out = new Float64Array( 4 );

var y = flatten4d.assign( x, [ 2, 1, 1, 2 ], false, out, 1, 0 );
// returns <Float64Array>[ 1, 2, 3, 4 ]

var bool = ( y === out );
// returns true

y = flatten4d.assign( x, [ 2, 1, 1, 2 ], true, out, 1, 0 );
// returns <Float64Array>[ 1, 3, 2, 4 ]

Notes

Both functions assume that all nested arrays have the same length (i.e., the input array is not a ragged array).

Examples

var flatten4d = require( '@stdlib/array/base/flatten4d' );

// Define a 2x2x2x2 array:
var x = [
    [
        [ [ 1, 2 ], [ 3, 4 ] ],
        [ [ 5, 6 ], [ 7, 8 ] ]
    ],
    [
        [ [ 9, 10 ], [ 11, 12 ] ],
        [ [ 13, 14 ], [ 15, 16 ] ]
    ]
];

var out = flatten4d( x, [ 0, 0, 0, 0 ], false );
// returns []

out = flatten4d( x, [ 0, 0, 0, 0 ], true );
// returns []

out = flatten4d( x, [ 1, 1, 1, 1 ], false );
// returns [ 1 ]

out = flatten4d( x, [ 1, 1, 1, 1 ], true );
// returns [ 1 ]

out = flatten4d( x, [ 1, 2, 2, 2 ], false );
// returns [ 1, 2, 3, 4, 5, 6, 7, 8 ]

out = flatten4d( x, [ 1, 2, 2, 2 ], true );
// returns [ 1, 5, 3, 7, 2, 6, 4, 8 ]

out = flatten4d( x, [ 2, 2, 2, 2 ], false );
// returns [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 ]

out = flatten4d( x, [ 2, 2, 2, 2 ], true );
// returns [ 1, 9, 5, 13, 3, 11, 7, 15, 2, 10, 6, 14, 4, 12, 8, 16 ]