# boxcoxinv

Compute the inverse of a one-parameter Box-Cox transformation.

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

## Usage

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


#### boxcoxinv( y, lambda )

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

var v = boxcoxinv( 1.0, 2.5 );
// returns ~1.6505

v = boxcoxinv( 4.0, 2.5 );
// returns ~2.6095

v = boxcoxinv( 10.0, 2.5 );
// returns ~3.6812

v = boxcoxinv( 2.0, 0.0 );
// returns ~7.3891

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

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

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

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


## Examples

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

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 = boxcoxinv( y[ i ], l[ j ] );
console.log( 'boxcoxinv(%d, %d) = %d', 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.
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