scipy.special.ncfdtrinc

scipy.special.ncfdtrinc(dfn, dfd, p, f) = <ufunc 'ncfdtrinc'>

Calculate non-centrality parameter for non-central F distribution.

This is the inverse with respect to nc of ncfdtr. See ncfdtr for more details.

Parameters:

dfn : array_like

Degrees of freedom of the numerator sum of squares. Range (0, inf).

dfd : array_like

Degrees of freedom of the denominator sum of squares. Range (0, inf).

p : array_like

Value of the cumulative distribution function. Must be in the range [0, 1].

f : array_like

Quantiles, i.e. the upper limit of integration.

Returns:

nc : float

Noncentrality parameter.

See also

ncfdtr

CDF of the non-central F distribution.

ncfdtri

Quantile function; inverse of ncfdtr with respect to f.

ncfdtridfd

Inverse of ncfdtr with respect to dfd.

ncfdtridfn

Inverse of ncfdtr with respect to dfn.

Examples

>>> from scipy.special import ncfdtr, ncfdtrinc

Compute the CDF for several values of nc:

>>> nc = [0.5, 1.5, 2.0]
>>> p = ncfdtr(2, 3, nc, 15)
>>> p
array([ 0.96309246,  0.94327955,  0.93304098])

Compute the inverse. We recover the values of nc, as expected:

>>> ncfdtrinc(2, 3, p, 15)
array([ 0.5,  1.5,  2. ])