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ssyr

Perform the symmetric rank 1 operation A = alpha*x*x^T + A.

Installation

npm install @stdlib/blas-base-ndarray-ssyr

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 ssyr = require( '@stdlib/blas-base-ndarray-ssyr' );

ssyr( arrays )

Performs the symmetric rank 1 operation A = alpha*x*x^T + A, where alpha is a scalar, x is a one-dimensional ndarray, and A is an N by N symmetric matrix.

var Float32Matrix = require( '@stdlib/ndarray-matrix-float32' );
var Float32Vector = require( '@stdlib/ndarray-vector-float32' );
var scalar2ndarray = require( '@stdlib/ndarray-from-scalar' );
var resolveEnum = require( '@stdlib/blas-base-matrix-triangle-resolve-enum' );

var x = new Float32Vector( [ 1.0, 2.0, 3.0 ] );
var A = new Float32Matrix( [ [ 1.0, 2.0, 3.0 ], [ 2.0, 1.0, 2.0 ], [ 3.0, 2.0, 1.0 ] ] );

var uplo = scalar2ndarray( resolveEnum( 'upper' ), {
    'dtype': 'int32'
});
var alpha = scalar2ndarray( 1.0, {
    'dtype': 'float32'
});

var y = ssyr( [ x, A, uplo, alpha ] );
// returns <ndarray>[ [ 2.0, 4.0, 6.0 ], [ 2.0, 5.0, 8.0 ], [ 3.0, 2.0, 10.0 ] ]

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

The function has the following parameters:

• arrays: array-like object containing the following ndarrays:

  • a one-dimensional input ndarray corresponding to x.
  • a two-dimensional input/output ndarray corresponding to A.
  • a zero-dimensional ndarray specifying whether the upper or lower triangular part of the symmetric matrix A should be referenced.
  • a zero-dimensional ndarray containing a scalar constant corresponding to alpha.

Examples

var discreteUniform = require( '@stdlib/random-discrete-uniform' );
var zeros = require( '@stdlib/ndarray-zeros' );
var scalar2ndarray = require( '@stdlib/ndarray-from-scalar' );
var resolveEnum = require( '@stdlib/blas-base-matrix-triangle-resolve-enum' );
var ndarray2array = require( '@stdlib/ndarray-to-array' );
var ssyr = require( '@stdlib/blas-base-ndarray-ssyr' );

var opts = {
    'dtype': 'float32'
};

var x = discreteUniform( [ 3 ], 0, 10, opts );
var A = zeros( [ 3, 3 ], opts );

var uplo = scalar2ndarray( resolveEnum( 'upper' ), {
    'dtype': 'int32'
});
var alpha = scalar2ndarray( 1.0, opts );

var out = ssyr( [ x, A, uplo, alpha ] );
console.log( ndarray2array( out ) );

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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 © 2016-2026. The Stdlib Authors.