fDistributionComplInv

The F distribution, its complement, and inverse.

The F density function (also known as Snedcor's density or the variance ratio density) is the density of x = (u1/df1)/(u2/df2), where u1 and u2 are random variables having χ2 distributions with df1 and df2 degrees of freedom, respectively.

fDistribution returns the area from zero to x under the F density function. The complementary function, fDistributionCompl, returns the area from x to ∞ under the F density function.

The inverse of the complemented F distribution, fDistributionComplInv, finds the argument x such that the integral from x to infinity of the F density is equal to the given probability y.

Can be used to test whether the means of multiple normally distributed populations, all with the same standard deviation, are equal; or to test that the standard deviations of two normally distributed populations are equal.

  1. real fDistribution(int df1, int df2, real x)
  2. real fDistributionCompl(int df1, int df2, real x)
  3. real fDistributionComplInv(int df1, int df2, real p)
    real
    fDistributionComplInv
    (
    int df1
    ,
    int df2
    ,
    real p
    )

Parameters

df1 int

Degrees of freedom of the first variable. Must be >= 1

df2 int

Degrees of freedom of the second variable. Must be >= 1

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