Skip to content

README.md

Latest commit

 

History

History
312 lines (199 loc) · 8.76 KB

README.md

File metadata and controls

312 lines (199 loc) · 8.76 KB

svander

Generate a single-precision floating-point Vandermonde matrix.

Usage

var svander = require( '@stdlib/blas/ext/base/svander' );

svander( order, mode, M, N, x, strideX, out, ldo )

Generates a single-precision floating-point Vandermonde matrix.

var Float32Array = require( '@stdlib/array/float32' );

var x = new Float32Array( [ 1.0, 2.0, 3.0 ] );
var out = new Float32Array( 9 );

svander( 'row-major', -1, 3, 3, x, 1, out, 3 );
// out => <Float32Array>[ 1.0, 1.0, 1.0, 4.0, 2.0, 1.0, 9.0, 3.0, 1.0 ]

The function has the following parameters:

  • order: row-major (C-style) or column-major (Fortran-style) order.
  • mode: mode. If mode < 0, the function generates decreasing powers. If mode > 0, the function generates increasing powers.
  • M: number of rows in out and number of indexed elements in x.
  • N: number of columns in out.
  • x: input Float32Array.
  • strideX: stride length for x.
  • out: output matrix stored in linear memory as a Float32Array.
  • ldo: stride of the first dimension of out (a.k.a., leading dimension of the matrix out).

svander.ndarray( mode, M, N, x, strideX, offsetX, out, strideOut1, strideOut2, offsetOut )

Generates a single-precision floating-point Vandermonde matrix using alternative indexing semantics.

var Float32Array = require( '@stdlib/array/float32' );

var x = new Float32Array( [ 1.0, 2.0, 3.0 ] );
var out = new Float32Array( 9 );

svander.ndarray( -1, 3, 3, x, 1, 0, out, 3, 1, 0 );
// out => <Float32Array>[ 1.0, 1.0, 1.0, 4.0, 2.0, 1.0, 9.0, 3.0, 1.0 ]

The function has the following additional parameters:

  • offsetX: starting index for x.
  • strideOut1: stride length for the first dimension of out.
  • strideOut2: stride length for the second dimension of out.
  • offsetOut: starting index for out.

While typed array views mandate a view offset based on the underlying buffer, the offset parameters support indexing semantics based on starting indices. For example,

var Float32Array = require( '@stdlib/array/float32' );

var x = new Float32Array( [ 0.0, 1.0, 2.0, 3.0 ] );
var out = new Float32Array( 9 );

svander.ndarray( -1, 3, 3, x, 1, 1, out, 3, 1, 0 );
// out => <Float32Array>[ 1.0, 1.0, 1.0, 4.0, 2.0, 1.0, 9.0, 3.0, 1.0 ]

Notes

  • If M <= 0 or N <= 0, both functions return out unchanged.

Examples

var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
var Float32Array = require( '@stdlib/array/float32' );
var svander = require( '@stdlib/blas/ext/base/svander' );

var M = 3;
var N = 4;

var x = discreteUniform( M, 0, 10, {
    'dtype': 'float32'
});
var out = new Float32Array( M*N );

svander( 'row-major', -1, M, N, x, 1, out, N );
console.log( out );

out = new Float32Array( M*N );
svander.ndarray( -1, M, N, x, 1, 0, out, N, 1, 0 );
console.log( out );

C APIs

Usage

#include "stdlib/blas/ext/base/svander.h"

stdlib_strided_svander( order, mode, M, N, *X, strideX, *Out, LDO )

Generates a single-precision floating-point Vandermonde matrix.

#include "stdlib/blas/base/shared.h"

const float x[ 3 ] = { 1.0f, 2.0f, 3.0f };
float Out[ 3*3 ] = { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };

stdlib_strided_svander( CblasRowMajor, -1.0f, 3, 3, x, 1, Out, 3 );

The function accepts the following arguments:

  • order: [in] CBLAS_LAYOUT storage layout.
  • mode: [in] float mode. If mode < 0, the function generates decreasing powers. If mode > 0, the function generates increasing powers.
  • M: [in] CBLAS_INT number of rows in Out and number of indexed elements in X.
  • N: [in] CBLAS_INT number of columns in Out.
  • X: [in] float* input array.
  • strideX: [in] CBLAS_INT stride length for X.
  • Out: [out] float* output matrix.
  • LDO: [in] CBLAS_INT stride of the first dimension of Out (a.k.a., leading dimension of the matrix Out).
void API_SUFFIX(stdlib_strided_svander)( const CBLAS_LAYOUT order, const float mode, const CBLAS_INT M, const CBLAS_INT N, const float *X, const CBLAS_INT strideX, float *Out, const CBLAS_INT LDO );

stdlib_strided_svander_ndarray( mode, M, N, *X, strideX, offsetX, *Out, strideOut1, strideOut2, offsetOut )

Generates a single-precision floating-point Vandermonde matrix using alternative indexing semantics.

#include "stdlib/blas/base/shared.h"

const float x[ 3 ] = { 1.0f, 2.0f, 3.0f };
float Out[ 3*3 ] = { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };

stdlib_strided_svander_ndarray( -1.0f, 3, 3, x, 1, 0, Out, 3, 1, 0 );

The function accepts the following arguments:

  • mode: [in] float mode. If mode < 0, the function generates decreasing powers. If mode > 0, the function generates increasing powers.
  • M: [in] CBLAS_INT number of rows in Out and number of indexed elements in X.
  • N: [in] CBLAS_INT number of columns in Out.
  • X: [in] float* input array.
  • strideX: [in] CBLAS_INT stride length for X.
  • offsetX: [in] CBLAS_INT starting index for X.
  • Out: [out] float* output matrix.
  • strideOut1: [in] CBLAS_INT stride length for the first dimension of Out.
  • strideOut2: [in] CBLAS_INT stride length for the second dimension of Out.
  • offsetOut: [in] CBLAS_INT starting index for Out.
void API_SUFFIX(stdlib_strided_svander_ndarray)( const float mode, const CBLAS_INT M, const CBLAS_INT N, const float *X, const CBLAS_INT strideX, const CBLAS_INT offsetX, float *Out, const CBLAS_INT strideOut1, const CBLAS_INT strideOut2, const CBLAS_INT offsetOut );

Examples

#include "stdlib/blas/ext/base/svander.h"
#include "stdlib/blas/base/shared.h"
#include <stdio.h>

int main( void ) {
    // Define the input array:
    const float x[ 3 ] = { 1.0f, 2.0f, 3.0f };

    // Define a 3x3 output array stored in row-major order:
    float Out[ 3*3 ] = { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };

    // Specify the number of rows and columns:
    const int M = 3;
    const int N = 3;

    // Perform operation:
    stdlib_strided_svander( CblasRowMajor, -1.0f, M, N, x, 1, Out, N );

    // Print the result:
    for ( int i = 0; i < M; i++ ) {
        for ( int j = 0; j < N; j++ ) {
            printf( "Out[%i,%i] = %f\n", i, j, Out[ (i*N)+j ] );
        }
    }
}