# symmetrical_uncertainty: Estimating Symmetrical Uncertainty of two categorical... In msu: Multivariate Symmetric Uncertainty and Other Measurements

## Description

Symmetrical uncertainty (SU) is the product of a normalization of the information gain (`IG`) with respect to entropy. SU(X,Y) is a value in the range [0,1], where SU(X,Y) = 0 if X and Y are totally independent and SU(X,Y) = 1 if X and Y are totally dependent.

## Usage

 ```1 2 3``` ```symmetrical_uncertainty(x, y) SU(x, y) ```

## Arguments

 `x` A factor as the represented categorical variable. `y` A factor as the represented categorical variable.

## Value

Symmetrical uncertainty estimation based on Sannon entropy. The result is `round`ed to 7 decimal places.

`msu`
 ```1 2 3 4 5 6 7 8 9``` ```# completely predictable symmetrical_uncertainty(factor(c(0,1,0,1)), factor(c(0,1,0,1))) # XOR factor variables symmetrical_uncertainty(factor(c(0,0,1,1)), factor(c(0,1,1,0))) symmetrical_uncertainty(factor(c(0,1,0,1)), factor(c(0,1,1,0))) ## Not run: symmetrical_uncertainty(c(0,1,0,1), c(0,1,1,0)) ## End(Not run) ```