The ngspice scripting language may be used to run Monte-Carlo simulations with statistically varying device or model parameters. Calls to the functions sgauss(0) or sunif(0) (see 17.2) will return Gaussian or uniform distributed random numbers (real numbers), stored in a vector. You may define (see 17.5.15) your own function using sgauss or sunif, e.g. to change the mean or range. In a loop (see 17.6) then you may call the alter (17.5.3) or altermod (17.5.4) statements with random parameters followed by an analysis like op, dc, ac, tran or other.