Hello, I apologize for such a basic question, but I have been trying to do this in multiple packages without much success. I am trying to set up a state space model for Kalman filtering. I am using package dlm. The DLM is specified by: observation: y(t) = F(t)*theta(t) + v(t) state: theta(t) = G(t)*theta(t-1) + w(t) I have no problem setting up a simple example where F is constant. I am trying to set up a model where F(t) (the output matrix) has time varying values (x1(t),x2(t)). I keep getting an incompatible dimension error despite trying a number of different permutations. I do have a copy of the Petris book, but I haven't had a chance to give it a thorough read at this point. Any assistance would be greatly appreciated: Example code: #n x p output matrix FMat<-cbind(rnorm(123),rnorm(123)) #p x p state transition matrix GMat<-matrix(c(1,0,0,1),ncol=2) #p x p system noise distribution WMat<-matrix(c(0.02,0,0,0.02),ncol=2) # nxn measurement noise Vmat<-matrix(0,ncol=123,nrow=123) diag(Vmat)<-0.02 #initial state mean and variance m0Vec<-c(1,1) c0Vec<-c(0.05,0.05) ssMod<-dlm(FF=FMat,V=Vmat,GG=GMat,W=WMat,m0=m0Vec,C0=c0Vec) Resulting error: Error in dlm(FF = FMat, V = Vmat, GG = GMat, W = WMat, m0 = m0Vec, C0 = c0Vec) : Incompatible dimensions of matrices [[alternative HTML version deleted]]