I have the joint distribution of three discrete random variables z1, z2 and z3 which is captured by "z" and "prob" as described below.
For example, the probability for z1=0.46667, z2=-1 and z3=-1 is 2.752e-13. Also, the probability adds up to 1. > head(z) z1 z2 z3 [1,] -0.46667 -1.0000 -1.0000 [2,] -0.33333 -0.9333 -0.9333 [3,] -0.20000 -0.8667 -0.8667 [4,] -0.06667 -0.8000 -0.8000 [5,] 0.06667 -0.7333 -0.7333 [6,] 0.20000 -0.6667 -0.6667> prob[1:5][1] 2.752e-13 3.210e-12 1.348e-11 2.656e-11 2.656e-11> sum(prob)[1] 1 I want to put the distribution into a joint probability table. I use the following code. But the probability no longer adds up to 1. > z1 <- sort(unique(z[,1])); z2 <- sort(unique(z[,2])); z3 <- > sort(unique(z[,3]))> P <- array(0, dim=c(length(z1),length(z2),length(z3)), > dimnames=list(A=z1, H=z2, M=z3))> > for (i in 1:(dim(z)[1])){+ ind <- > z[i,]+ P[dimnames(P)$A==ind[1], dimnames(P)$H==ind[2], > dimnames(P)$M==ind[3]] <- prob[i] + }> sum(P)[1] 37.5 The problem is when we look z1 as below, there are lot of repeated values. > unique(z[,1]) [1] -0.46667 -0.33333 -0.20000 -0.06667 0.06667 0.20000 > 0.33333 0.46667 -0.53333 -0.40000 [11] -0.26667 -0.13333 0.00000 0.13333 0.26667 0.40000 0.53333 -0.60000 -0.06667 0.06667 [21] 0.60000 -0.66667 -0.13333 0.13333 0.66667 -0.73333 -0.60000 -0.20000 0.20000 0.60000 [31] 0.73333 -0.80000 -0.53333 -0.26667 0.26667 0.53333 0.80000 -0.86667 -0.46667 -0.33333 [41] 0.33333 0.46667 0.86667 -0.93333 -0.40000 0.40000 0.93333 -1.00000 -0.46667 -0.33333 [51] 0.33333 0.46667 1.00000 -0.53333 -0.26667 0.26667 0.53333 -0.20000 0.20000 -0.66667 [61] -0.13333 0.13333 0.66667 -0.73333 -0.06667 0.06667 0.73333 -0.20000 0.20000 -0.13333 [71] 0.13333 -0.06667 0.06667 -0.06667 0.06667 Is there a way to fix this? Any idea and suggestions? Thanks very much!! Hanna [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.