Dear Statistics-Experts, Assume you have given a new and untested pseudo-random number generator (prng) and you want to test if it "works". The distribution function (cdf) from which the prng is supposed to sample is known. Further, you are given some finite (large) sample from the prng. If the sample is one-dimensional, we can apply the cdf to it and test the sample for being realizations of i.i.d. U[0,1]-random variables. However, my problem is, that the sample is not one-dimensional but multidimensional (say I have 10000 observations from the prng where each observation is 100 dimensional). How can I test the prng? One idea would be to apply the known cdf to the data to obtain a one- dimensional sample, but the corresponding theoretical distribution function (often called 'probability integral transform') is also not known. Is there a simple way (or any way) to test such a prng? Most papers I found deal with the standard uniform case, which is of course easy to test (Kolmogorov-Smirnov, Anderson-Darling, ...). Thanks in advance! Marius m_hofert at web.de PS: Sorry, this question is not directly related to R, but I hope you can help me anyway.