Chi Distribution
The probability density function and cumulative distribution function are
 |  |  | (1) |
 | |  | (2) |
where
is the Regularized Gamma Function. | |  | (3) |
 | |  | (4) |
 | |  | |
 |  | (5) | |
 | |  | |
|  | (6) |
where 
is the Mean, 
the Variance, 
the Skewness, and 
theKurtosis. For 
, the 
distribution is a Half-Normal Distribution with 
. For 
, itis a Rayleigh Distribution with 
.