vector.matrixbuilder.triangularmask.md

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MatrixBuilder.triangularMask() method

Constructs a matrix that has ones on and above the diagonal, and zeros elsewhere.

Signature:

triangularMask(shape: MatrixShape, lower?: boolean, includeDiagonal?: boolean): M;

Parameters

Parameter	Type	Description
shape	MatrixShape	The shape of the matrix as a tuple [m, n]
lower	boolean	(Optional) If true, the matrix will have ones below the diagonal rather than above. false by default.
includeDiagonal	boolean	(Optional) If false, entries on the diagonal will be zero. true by default.

Returns:

M

The triangular matrix

Example

const upper = matrixBuilder.triangularMask([4, 4]);

// [ 1 1 1 1 ]
// [ 0 1 1 1 ]
// [ 0 0 1 1 ]
// [ 0 0 0 1 ]

const lower = matrixBuilder.triangularMask([4, 4], true);

// [ 1 0 0 0 ]
// [ 1 1 0 0 ]
// [ 1 1 1 0 ]
// [ 1 1 1 1 ]

const strictUpper = matrixBuilder.triangularMask([4, 4], false, false);

// [ 0 1 1 1 ]
// [ 0 0 1 1 ]
// [ 0 0 0 1 ]
// [ 0 0 0 0 ]