External module "math/base/special/gammaincinv/docs/types/index.d"

Export assignment gammaincinv

• gammaincinv(p: number, a: number, upper?: undefined | false | true): number

• Inverts the lower gamma function; i.e., computes xr such that P(a,xr) = p.

  Notes

  • In contrast to a more commonly used definition, the first argument is the probability p and the second argument is the scale factor a.
  • By default, the function inverts the lower regularized incomplete gamma function, P(x,a). To invert the upper function Q(x,a), set the upper argument to true.
  • If provided p < 0 or p > 1, the function returns NaN.

  Parameters

  • p: number

    probability value

  • a: number

    scale parameter

  • Optional upper: undefined | false | true

    boolean indicating if the function should invert the upper tail of the incomplete gamma function instead; i.e., compute xr such that Q(a,xr) = p (default: false)

  Returns number

  function value of the inverse

  Example

  javascript var y = gammaincinv( 0.5, 2.0 ); // returns ~1.678

  Example

  javascript var y = gammaincinv( 0.1, 10.0 ); // returns ~6.221

  Example

  javascript var y = gammaincinv( 0.75, 3.0 ); // returns ~3.92

  Example

  javascript var y = gammaincinv( 0.75, 3.0, true ); // returns ~1.727

  Example

  javascript var y = gammaincinv( 0.75, NaN ); // returns NaN

  Example

  var y = gammaincinv( NaN, 3.0 );
  // returns NaN