1 The nearest neighbour distribution of N points in a 3d-Volume with radius R is given by W(r) = 1 - exp[ - N (r/r)^3] and this is a Weibull distribution and not a Poisson distribution. The WIKI article, while correct, is a typical case where high level statisticians are trying to make simple things look very complicated.

2 Comparing the experimental distribution with the above prediction is made complicated as the manufactured object has small hard spheres that push each other apart in the manufacturing process and the Weibull is modified anyway. 3 I am sill searching for a 3d spatial characterization coefficient that differentiates between purely random arrangements and gradual regular arrangements. Heinz -----Original Message----- From: users [mailto:users-boun...@lists.scilab.org] On Behalf Of Rafael Guerra Sent: 09 February 2018 10:17 To: Users mailing list for Scilab <users@lists.scilab.org> Subject: Re: [Scilab-users] spatial correlation coefficient: Is the MATLAB corrcoef function doing the job? Q: "I have 10,000 xyz data and want to know, if there is some regularity in them or if they are more or less random" A: look for tests of spatial randomness (https://en.wikipedia.org/wiki/Complete_spatial_randomness ) . If The experimental nearest neighbor distribution obtained previously can be compared to the expected Poisson distribution. _______________________________________________ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users