Hi! At Thu, 1 Dec 2005 01:01:39 +0900, Stephen Waits wrote: > Try this, if you don't need high performance... > > def rand_normal_float(mean = 0.0, variance = 1.0) > # sum 12 random numbers uniformly distributed in [0,1] > sum = 0.0 > 12.times { sum += Kernel.rand } > # adjust for mean and variance > (variance.to_f * (sum - 6.0)) + mean.to_f > end My mathematical intuition says that the Gaussian distribution is achieved as the limit of the above replacing 12 by N (and 6 by N/2) and then computing the limit for N versus infinity. Without knowing the quality of the approximation of using 12 in place of infinity the approximation is of no practical value. Besides that summing up pseudo-random numbers may decrease their randomness. Josef 'Jupp' Schugt -- Diese E-Mail wurde moeglicherweise erst mehrere Stunden nach ihrer Fertigstellung versendet, um Onlinekosten zu sparen. This e-mail has possibly been sent several hours after composition in order to reduce online costs.