https://www.mathworks.com/help/matlab/ref/gammainc.html
gammainc - Regularized incomplete gamma function - MATLAB
This MATLAB function returns the regularized lower incomplete gamma function evaluated at the elements of X and A.
incomplete gamma functionmatlab
https://www.mathworks.com/help/matlab/ref/gammaincinv.html
gammaincinv - Inverse of regularized incomplete gamma function - MATLAB
This MATLAB function returns the inverse of the regularized lower incomplete gamma function evaluated at the elements of Y and A, such that Y = gammainc(X,A).
incomplete gamma functioninversematlab