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scipy.special.fdtr¶
- scipy.special.fdtr(dfn, dfd, x) = <ufunc 'fdtr'>¶
F cumulative distribution function.
Returns the value of the cumulative density function of the F-distribution, also known as Snedecor’s F-distribution or the Fisher-Snedecor distribution.
The F-distribution with parameters dn and dd is the distribution of the random variable,
X=Un/dnUd/dd,where Un and Ud are random variables distributed χ2, with dn and dd degrees of freedom, respectively.
Parameters: dfn : array_like
First parameter (positive float).
dfd : array_like
Second parameter (positive float).
x : array_like
Argument (nonnegative float).
Returns: y : ndarray
The CDF of the F-distribution with parameters dfn and dfd at x.
Notes
The regularized incomplete beta function is used, according to the formula,
F(dn,dd;x)=Ixdn/(dd+xdn)(dn/2,dd/2).Wrapper for the Cephes [R357] routine fdtr.
References
[R357] (1, 2) Cephes Mathematical Functions Library, http://www.netlib.org/cephes/index.html