FisherZ: Fisher's Z transformation
In DiagTest3Grp: Diagnostic test summary measures for three ordinal groups

Description Usage Arguments Details Value Note Author(s) References See Also Examples

Fisher's Z transformation on an estimator in the range of 0~1.

1	FisherZ(x)

`x`	A numeric value, an estimator within the range of 0 to 1.

Fisher's Z transformation transform an estimator x which is in the range of 0 and 1 to z=1/2*log((1+x)/(1-x)). The transformation is useful for skewed distribution of a variable between 0 and 1. z after transformation will be more normally distributed. Fisher's Z transformation has been implemented on correlation coefficient, volume under ROC.

Return a numeric value—the transformed estimator z.

Bug reports, malfunctioning, or suggestions for further improvements or contributions can be sent to Jingqin Luo <rosy@wubios.wustl.edu>.

Jingqin Luo

Fisher, R.A. (1915) Frequency distribution of the values of the correlation coefficient in samples of an indefinitely large population. Biometrika 10 (4) 507

Xiong, C. and van Belle, G. and Miller, J.P. and Morris, J.C. (2006) Measuring and Estimating Diagnostic Accuracy When There Are Three Ordinal Diagnostic Groups. Statistics In Medicine 25 7 1251–1273.

FisherZ.Var