scipy.special.ncfdtridfn(p, f, dfd, nc) = <ufunc 'ncfdtridfn'>

Calculate degrees of freedom (numerator) for the noncentral F-distribution.

See ncfdtr for more details.


The value of the cumulative noncentral F distribution is not necessarily monotone in either degrees of freedom. There thus may be two values that provide a given CDF value. This routine assumes monotonicity and will find an arbitrary one of the two values.