Hi, I am having problems with the poisson random number generators of both Numarray and Numeric. I can't replicate it when calling the function from the python cosonle, but it has consistently malfunctioned when used within one of my scripts. What happens is that it frequently return a value greater than zero when called with zero mean: poisson(0.0) Unfortunately My program is too big to send attached but I have confirmed the malfunction by printing both the mean and the result whenever it spits out a wrong result. This is very weird indeed, I have run poisson millions of times by itsel on the python console, without any problems... I hope it is some stupid mistake, but when I replace the poisson function call within my program by the R equivalent command (rpois) via the rpy wrapper, everything works just fine... any Ideas? -- Flávio Codeço Coelho registered Linux user # 386432 --------------------------- Great spirits have always found violent opposition from mediocrities. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence. Albert Einstein