scipy.special.gammaincinv#
- scipy.special.gammaincinv(a, y, out=None) = <ufunc 'gammaincinv'>#
- Inverse to the regularized lower incomplete gamma function. - Given an input \(y\) between 0 and 1, returns \(x\) such that \(y = P(a, x)\). Here \(P\) is the regularized lower incomplete gamma function; see - gammainc. This is well-defined because the lower incomplete gamma function is monotonic as can be seen from its definition in [dlmf].- Parameters:
- aarray_like
- Positive parameter 
- yarray_like
- Parameter between 0 and 1, inclusive 
- outndarray, optional
- Optional output array for the function values 
 
- Returns:
- scalar or ndarray
- Values of the inverse of the lower incomplete gamma function 
 
 - See also - gammainc
- regularized lower incomplete gamma function 
- gammaincc
- regularized upper incomplete gamma function 
- gammainccinv
- inverse of the regularized upper incomplete gamma function 
 - References [dlmf]- NIST Digital Library of Mathematical Functions https://dlmf.nist.gov/8.2#E4 - Examples - >>> import scipy.special as sc - It starts at 0 and monotonically increases to infinity. - >>> sc.gammaincinv(0.5, [0, 0.1 ,0.5, 1]) array([0. , 0.00789539, 0.22746821, inf]) - It inverts the lower incomplete gamma function. - >>> a, x = 0.5, [0, 0.1, 0.5, 1] >>> sc.gammainc(a, sc.gammaincinv(a, x)) array([0. , 0.1, 0.5, 1. ]) - >>> a, x = 0.5, [0, 10, 25] >>> sc.gammaincinv(a, sc.gammainc(a, x)) array([ 0. , 10. , 25.00001465])