QF

qf

The F (or Fisher-Snedecor) inverse distribution function

         x = qf(p,df1,df2)
	Input	p	probability
		df1,df2	degrees of freedom
		(p,df1,df2 can be scalar or matrix with common size)

	Output	F	inverse at p of the F cumulative distribution
			function with degrees of freedom df1, df2

	(the F law with  degrees of freedom df1 and df2
	 is the law of (X/df1)/(Y/df2)  where  X and Y
	 are independent Chisquare random variables 
	 with one degree of freedom)