nisp_expinv — Computes the Exponential quantile.
x = nisp_expinv ( p ) x = nisp_expinv ( p , lambda )
This function computes the Exponential Quantile.
Any scalar input argument is expanded to a matrix of doubles of the same size as the other input arguments.
Any optional input argument equal to the empty matrix will be set to its default value.
This function might be inaccurate when p is close to 1.
TODO : improve implementation (check inf, nan, etc...)