Hi!! I am trying to multiply 5 matrices and then using the inverse of that matrix for further computation. I read about precision problems from the archives and the suggestion was to use as.numeric while computing the products. I am still having problems with the results. Here is how I am using it
#Mn.mat<-(T.mat %*% Rz.mat %*% Q.mat %*% Rz.mat %*% T.mat) # I was doing this in one step which I have broken down into multiple steps as below. Mn1.mat<-matrix(as.numeric(T.mat %*% Rz.mat),nrow=4) Mn2.mat<-matrix(as.numeric(Mn1.mat %*% Q.mat),nrow=4) Mn3.mat<-matrix(as.numeric(Mn2.mat %*% Rz.mat),nrow=4) Mn.mat<-matrix(as.numeric( Mn3.mat %*% T.mat),nrow=4) For getting the inverse I am doing the following Mn.mat.inv<-qr.solve(Mn.mat) Will I run into precision problems when I do the above? Thanks ../Murli ______________________________________________ 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.
