zlaset

Set the off-diagonal elements and the diagonal elements of a double-precision complex floating-point matrix to specified values.

Usage

var zlaset = require( '@stdlib/lapack/base/zlaset' );

zlaset( order, uplo, M, N, alpha, beta, A, LDA )

Sets the off-diagonal elements and the diagonal elements of a double-precision complex floating-point matrix to specified values.

var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );
var real = require( '@stdlib/complex/float64/real' );
var imag = require( '@stdlib/complex/float64/imag' );

var A = new Complex128Array( 4 );

var alpha = new Complex128( 1.0, 2.0 );
var beta = new Complex128( 3.0, 4.0 );

zlaset( 'row-major', 'all', 2, 2, alpha, beta, A, 2 );

var z = A.get( 0 );
// returns <Complex128>

var re = real( z );
// returns 3.0

var im = imag( z );
// returns 4.0

z = A.get( 1 );
// returns <Complex128>

re = real( z );
// returns 1.0

im = imag( z );
// returns 2.0

The function has the following parameters:

• order: storage layout.
• uplo: specifies whether to set the upper or lower triangular/trapezoidal part of a matrix A.
• M: number of rows in A.
• N: number of columns in A.
• alpha: value assigned to off-diagonal elements.
• beta: value assigned to diagonal elements.
• A: input Complex128Array.
• LDA: stride of the first dimension of A (a.k.a., leading dimension of the matrix A).

Note that indexing is relative to the first index. To introduce an offset, use typed array views.

var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );
var real = require( '@stdlib/complex/float64/real' );
var imag = require( '@stdlib/complex/float64/imag' );

// Initial array:
var A0 = new Complex128Array( 5 );

// Create offset view:
var A1 = new Complex128Array( A0.buffer, A0.BYTES_PER_ELEMENT*1 ); // start at 2nd element

var alpha = new Complex128( 1.0, 2.0 );
var beta = new Complex128( 3.0, 4.0 );

zlaset( 'row-major', 'all', 2, 2, alpha, beta, A1, 2 );

var z = A0.get( 1 );
// returns <Complex128>

var re = real( z );
// returns 3.0

var im = imag( z );
// returns 4.0

zlaset.ndarray( uplo, M, N, alpha, beta, A, sa1, sa2, oa )

Sets the off-diagonal elements and the diagonal elements of a double-precision complex floating-point matrix to specified values using alternative indexing semantics.

var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );
var real = require( '@stdlib/complex/float64/real' );
var imag = require( '@stdlib/complex/float64/imag' );

var A = new Complex128Array( 4 );

var alpha = new Complex128( 1.0, 2.0 );
var beta = new Complex128( 3.0, 4.0 );

zlaset.ndarray( 'all', 2, 2, alpha, beta, A, 2, 1, 0 );

var z = A.get( 0 );
// returns <Complex128>

var re = real( z );
// returns 3.0

var im = imag( z );
// returns 4.0

z = A.get( 1 );
// returns <Complex128>

re = real( z );
// returns 1.0

im = imag( z );
// returns 2.0

The function has the following parameters:

• uplo: specifies whether to set the upper or lower triangular/trapezoidal part of a matrix A.
• M: number of rows in A.
• N: number of columns in A.
• alpha: value assigned to off-diagonal elements.
• beta: value assigned to diagonal elements.
• A: input Complex128Array.
• sa1: stride of the first dimension of A.
• sa2: stride of the second dimension of A.
• oa: starting index for A.

While typed array views mandate a view offset based on the underlying buffer, the offset parameter supports indexing semantics based on a starting index. For example,

var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );
var real = require( '@stdlib/complex/float64/real' );
var imag = require( '@stdlib/complex/float64/imag' );

var A = new Complex128Array( 5 );

var alpha = new Complex128( 1.0, 2.0 );
var beta = new Complex128( 3.0, 4.0 );

zlaset.ndarray( 'all', 2, 2, alpha, beta, A, 2, 1, 1 );

var z = A.get( 0 );
// returns <Complex128>

var re = real( z );
// returns 0.0

var im = imag( z );
// returns 0.0

z = A.get( 1 );
// returns <Complex128>

re = real( z );
// returns 3.0

im = imag( z );
// returns 4.0

Notes

• zlaset() corresponds to the LAPACK routine zlaset.

Examples

var Complex128Array = require( '@stdlib/array/complex128' );
var Complex128 = require( '@stdlib/complex/float64/ctor' );
var ndarray2array = require( '@stdlib/ndarray/base/to-array' );
var numel = require( '@stdlib/ndarray/base/numel' );
var shape2strides = require( '@stdlib/ndarray/base/shape2strides' );
var zlaset = require( '@stdlib/lapack/base/zlaset' );

var shape = [ 5, 8 ];
var order = 'row-major';
var strides = shape2strides( shape, order );

var N = numel( shape );

var A = new Complex128Array( N );
console.log( ndarray2array( A, shape, strides, 0, order ) );

var alpha = new Complex128( 1.0, 2.0 );
var beta = new Complex128( 3.0, 4.0 );

zlaset( order, 'all', shape[ 0 ], shape[ 1 ], alpha, beta, A, strides[ 0 ] );
console.log( ndarray2array( A, shape, strides, 0, order ) );

---

C APIs

Usage

TODO

TODO

TODO.

TODO

TODO

TODO

Examples

TODO