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# scipy.special.ncfdtridfn

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

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

  See `ncfdtr` for more details.

  Notes

  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.