Skip to main content
`Ctrl`+`K`

# scipy.special.bdtri

scipy.special.bdtri(k, n, y, out=None) = <ufunc 'bdtri'>

  Inverse function to `bdtr` with respect to p.

  Finds the event probability p such that the sum of the terms 0 through k of the binomial probability density is equal to the given cumulative probability y.

  Parameters:
    karray_like

      Number of successes (float), rounded down to the nearest integer.

    narray_like

      Number of events (float)

    yarray_like

      Cumulative probability (probability of k or fewer successes in n events).

    outndarray, optional

      Optional output array for the function values

  Returns:
    pscalar or ndarray

      The event probability such that bdtr(lfloor k rfloor, n, p) = y.

  See also

  `bdtr`
  `betaincinv`

  Notes

  The computation is carried out using the inverse beta integral function and the relation,:

      1 - p = betaincinv(n - k, k + 1, y).

  Wrapper for the Cephes [1] routine `bdtri`.

  References

  [1]

  Cephes Mathematical Functions Library, http://www.netlib.org/cephes/