# scipy.special.chdtri

scipy.special.chdtri(v, p, out=None) = <ufunc 'chdtri'>

  Inverse to `chdtrc` with respect to x.

  Returns x such that `chdtrc(v, x) == p`.

  Parameters:
    v array_like

      Degrees of freedom.

    p array_like

      Probability.

    out ndarray, optional

      Optional output array for the function results.

  Returns:
    x scalar or ndarray

      Value so that the probability a Chi square random variable with v degrees of freedom is greater than x equals p.

  See also

  `chdtrc`, `chdtr`, `chdtriv`

  References

  [1]

  Chi-Square distribution, https://www.itl.nist.gov/div898/handbook/eda/section3/eda3666.htm

  Examples

      >>> import scipy.special as sc

  It inverts `chdtrc`.

      >>> v, p = 1, 0.3
      >>> sc.chdtrc(v, sc.chdtri(v, p))
      0.3
      >>> x = 1
      >>> sc.chdtri(v, sc.chdtrc(v, x))
      1.0