Calculate the L2-norm of a vector.
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Calculate the L2-norm of a vector.
bash
npm install @stdlib/blas-base-gnrm2script tag without installation and bundlers, use the [ES Module][es-module] available on the [esm][esm-url] branch (see [README][esm-readme]).deno][deno-url] branch (see [README][deno-readme] for usage intructions).umd][umd-url] branch (see [README][umd-readme]).javascript
var gnrm2 = require( '@stdlib/blas-base-gnrm2' );javascript
var x = [ 1.0, -2.0, 2.0 ];
var z = gnrm2( x.length, x, 1 );
// returns 3.0Array][mdn-array] or [typed array][mdn-typed-array].N and stride parameters determine which elements in the strided array are accessed at runtime. For example, to compute the [L2-norm][l2-norm] of every other element:javascript
var x = [ 1.0, 2.0, 2.0, -7.0, -2.0, 3.0, 4.0, 2.0 ];
var z = gnrm2( 4, x, 2 );
// returns 5.0typed array][mdn-typed-array] views.javascript
var Float64Array = require( '@stdlib/array-float64' );
var x0 = new Float64Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ] );
var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
var z = gnrm2( 4, x1, 2 );
// returns 5.0N is less than or equal to 0, the function returns 0.javascript
var x = [ 1.0, -2.0, 2.0 ];
var z = gnrm2.ndarray( x.length, x, 1, 0 );
// returns 3.0typed array][mdn-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, to calculate the [L2-norm][l2-norm] for every other value in the strided array starting from the second value:javascript
var x = [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ];
var z = gnrm2.ndarray( 4, x, 2, 1 );
// returns 5.0N <= 0, both functions return 0.0.gnrm2() corresponds to the [BLAS][blas] level 1 function [dnrm2][dnrm2] with the exception that this implementation works with any array type, not just Float64Arrays. Depending on the environment, the typed versions ([dnrm2][@stdlib/blas/base/dnrm2], [snrm2][@stdlib/blas/base/snrm2], etc.) are likely to be significantly more performant.@stdlib/array-base/accessor][@stdlib/array/base/accessor]).javascript
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var gnrm2 = require( '@stdlib/blas-base-gnrm2' );
var opts = {
'dtype': 'float64'
};
var x = discreteUniform( 10, -100, 100, opts );
console.log( x );
var out = gnrm2( x.length, x, 1 );
console.log( out );
