chiSqrDistribution

χ² cumulative distribution function and its complement.

Returns the area under the left hand tail (from 0 to x) of the Chi square probability density function with v degrees of freedom. The complement returns the area under the right hand tail (from x to ∞).

chiSqrDistribution(x | v) = ($(INTEGRATE 0, x) t^v/2-1 e^-t/2 dt ) / 2^v/2 $(GAMMA)(v/2)

chiSqrDistributionCompl(x | v) = ($(INTEGRATE x, ∞) t^v/2-1 e^-t/2 dt ) / 2^v/2 $(GAMMA)(v/2)