@stdlib/math-base-special-boxcox1pinv NPM

boxcox1pinv

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Compute the inverse of a one-parameter Box-Cox transformation for 1+x.

To compute the inverse of a one-parameter Box-Cox transformation, one finds the x such that

Installation

npm install @stdlib/math-base-special-boxcox1pinv

Usage

var boxcox1pinv = require( '@stdlib/math-base-special-boxcox1pinv' );

boxcox1pinv( y, lambda )

Computes the inverse of a one-parameter Box-Cox transformation for 1+x.

var v = boxcox1pinv( 1.0, 2.5 );
// returns ~0.6505

v = boxcox1pinv( 4.0, 2.5 );
// returns ~1.6095

v = boxcox1pinv( 10.0, 2.5 );
// returns ~2.6812

v = boxcox1pinv( 2.0, 0.0 );
// returns ~6.3891

v = boxcox1pinv( -1.0, 2.5 );
// returns NaN

v = boxcox1pinv( 0.0, -1.0 );
// returns 0.0

v = boxcox1pinv( 1.0, NaN );
// returns NaN

v = boxcox1pinv( NaN, 3.1 );
// returns NaN

Examples

var incrspace = require( '@stdlib/array-base-incrspace' );
var boxcox1pinv = require( '@stdlib/math-base-special-boxcox1pinv' );

var y = incrspace( -1.0, 10.0, 1.0 );
var l = incrspace( -0.5, 5.0, 0.5 );

var b;
var i;
var j;
for ( i = 0; i < y.length; i++ ) {
    for ( j = 0; j < l.length; j++ ) {
        b = boxcox1pinv( y[ i ], l[ j ] );
        console.log( 'boxcox1pinv(%d, %d) = %d', y[ i ], l[ j ], b );
    }
}

C APIs

Usage

#include "stdlib/math/base/special/boxcox1pinv.h"

stdlib_base_boxcox1pinv( y, lambda )

Computes the inverse of a one-parameter Box-Cox transformation of 1+x.

double out = stdlib_base_boxcox1pinv( 1.0, 2.5 );
// returns ~0.6505

out = stdlib_base_boxcox1pinv( 4.0, 2.5 );
// returns ~1.6095

The function accepts the following arguments:

y: [in] double input value.
lambda: [in] double power parameter.

double stdlib_base_boxcox1pinv ( const double y, const double lambda );

Examples

#include "stdlib/math/base/special/boxcox1pinv.h"
#include <stdio.h>

int main( void ) {
    const double y[] = { -1.0, 10.0, 1.0 };
    const double l[] = { -0.5, 5.0, 0.5 };

    double b;
    int i;
    int j;
    for ( i = 0; i < 3; i++ ) {
        for ( j = 0; j < 3; j++ ){
            b = stdlib_base_boxcox1pinv( y[ i ], l[ j ] );
            printf ( "boxcox1pinv(%lf, %lf) = %lf\n", y[ i ], l[ j ], b );
        }
    }
}

References

Box, G. E. P., and D. R. Cox. 1964. "An Analysis of Transformations." Journal of the Royal Statistical Society. Series B (Methodological) 26 (2). [Royal Statistical Society, Wiley]: 211–52. http://www.jstor.org/stable/2984418.

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.