Hello, I have the following problem: I have a set of n matrix equations in the form of : [b1] = [A] * [b0] [b2] = [A] * [b1] etc. vertical vectors [b0], [b1], ... are GIVEN. We try to estimate matrix A. As there are many equations (more than cells in matrix A) the system has no solutions. A is transition matrix (stochastic matrix) or markov process, so the sum of each row = 1 and each entry is probability (aij in <0;1>). I tried to estimate A by using constrOptim the following way, but apparently it won't work on matrices.
fr <- function(x) { x%*%matrix(c(2,5,6), 3,1)-matrix(c(5,4,2), 3,1) x%*%matrix(c(6,2,3), 3,1)-matrix(c(1,1,1), 3,1) x%*%matrix(c(6,1,2), 3,1)-matrix(c(3,4,1), 3,1) } constrOptim(matrix(c(0.5,0.4,0.1,0.2,0.3,0.5,0.5,0.2,0.3),3,3), fr, NULL, ui=matrix(c(1,0,0,0,1,0,0,0,1),3,3), ci=matrix(c(-.00001 ,-.00001,-.00001,-.00001,-.00001,-.00001,-.00001,-.00001,-.00001),3,3)) It produces the following error: "Error in ui %*% theta : non-conformable arguments" Kind regards and thanks for help Jacob [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list 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.