README.md

colcat

Concatenate a list of one-dimensional or two-dimensional ndarrays as columns.

Usage

var colcat = require( '@stdlib/ndarray/colcat' );

colcat( arrays )

Concatenates a list of one-dimensional or two-dimensional ndarrays as columns.

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

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

var y = array( [ [ 4.0, 5.0 ], [ 6.0, 7.0 ], [ 8.0, 9.0 ] ] );
// returns <ndarray>[ [ 4.0, 5.0 ], [ 6.0, 7.0 ], [ 8.0, 9.0 ] ]

var out = colcat( [ x, y ] );
// returns <ndarray>[ [ 1.0, 4.0, 5.0 ], [ 2.0, 6.0, 7.0 ], [ 3.0, 8.0, 9.0 ] ]

The function accepts the following arguments:

• arrays: a list of input ndarrays. The data type of the output ndarray is determined by applying type promotion rules to the list of input ndarrays. If provided ndarrays having different memory layouts, the output ndarray has the default order.

colcat.assign( arrays, out )

Concatenates a list of one-dimensional or two-dimensional ndarrays as columns and assigns results to a provided output ndarray.

var array = require( '@stdlib/ndarray/array' );
var zeros = require( '@stdlib/ndarray/zeros' );

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

var y = array( [ [ 4.0, 5.0 ], [ 6.0, 7.0 ], [ 8.0, 9.0 ] ] );
// returns <ndarray>[ [ 4.0, 5.0 ], [ 6.0, 7.0 ], [ 8.0, 9.0 ] ]

var z = zeros( [ 3, 3 ] );
// returns <ndarray>[ [ 0.0, 0.0, 0.0 ], [ 0.0, 0.0, 0.0 ], [ 0.0, 0.0, 0.0 ] ]

var out = colcat.assign( [ x, y ], z );
// returns <ndarray>[ [ 1.0, 4.0, 5.0 ], [ 2.0, 6.0, 7.0 ], [ 3.0, 8.0, 9.0 ] ]

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

The function accepts the following arguments:

• arrays: a list of input ndarrays. Must promote to a data type which can be (mostly) safely cast to the data type of the output ndarray.
• out: output ndarray. Must be a two-dimensional ndarray.

• One-dimensional input ndarrays having length N are promoted to two-dimensional ndarrays having shape [N, 1].
• Input ndarrays must have the same number of rows.

Examples

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

var x = discreteUniform( [ 3 ], 0, 10, {
    'dtype': 'generic'
});
console.log( ndarray2array( x ) );

var y = discreteUniform( [ 3, 2 ], 0, 10, {
    'dtype': 'generic'
});
console.log( ndarray2array( y ) );

var out = colcat( [ x, y ] );
console.log( ndarray2array( out ) );