Fcdf
Fcdf-func
Description
Computes /math-800618943025315f869e4e1f09471012.png "F") cumulative distribution function at f, with parameters ndf, fdf, and tail. The parameters of ndf and fdf must all be positive, and the values in f must be positive. The parameter tail determines the returned probability is the lower tailed or upper tailed.
The result, prob, is the probability that a single observation from a distribution with parameters ndf and fdf will fall in the interval [0, f] for lower-tailed, [f, /math-9ab0347369b93587a1fc8dbd6c6a8862.png "+\infty") ] for upper-tailed.
Syntax
double prob = fcdf(double f, double ndf, double fdf[, int tail])
Parameters
f
- Input, the value of the
/math-433e53f50d647e039aac4cb769c6ab10.png "F") variate,/math-aa9d3c3404bcef58965e4bb1fe9fb23c.png "f") . /math-20a70b758b09844f80bdfd9912f3a436.png "0\leq f<+\infty")
ndf
- Input, the degrees of freedom of the numerator variance,
/math-ebfdd136331841a1b59f835c998ca593.png "\nu_1") , must be positive (/math-4a6d85780ffad6e0a269217a30463f6c.png "ndf>0.0") ).
fdf
- Input, the degrees of freedom of the denominator variance,
/math-1ff7af9a810bd160a7334c3de425ed9d.png "\nu_2") , must be positive (/math-6de2d5eb9029aa30da169a680424a4d1.png "fdf>0.0") ).
tail
-
Input, Optional. The tail probability type using for the F distribution
- 1 = the for upper tail probability
- 2 = the lower tail probability (Default if not set)
prob
- Output, the returned probability
Example
fcdf(1000,20,20,1)=; //ANS: 9.0714457299284E-26
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