If `v' the the vector in the first column and `k' is the constant, then the matrix has k^(j-1) * v in the jth column, right?
> k <- 27.5^seq(0, length=4) > k [1] 1.00 27.50 756.25 20796.88 > outer(1:5, k, "*") [,1] [,2] [,3] [,4] [1,] 1 27.5 756.25 20796.88 [2,] 2 55.0 1512.50 41593.75 [3,] 3 82.5 2268.75 62390.63 [4,] 4 110.0 3025.00 83187.50 [5,] 5 137.5 3781.25 103984.38 Andy > From: Rau, Roland > > Dear R-Helpers, > > I have a matrix where the first column is known. The second column is > the result of multiplying this first column with a constant > "const". The > third column is the result of multiplying the second column with > "const"..... > So far, I did it like this (as a simplified example): > > nr.of.columns <- 4 > > myconstant <- 27.5 > > mymatrix <- matrix(numeric(0), nrow=5, ncol=nr.of.columns) > > mymatrix[,1] <- 1:5 > > for (i in 2:nr.of.columns) { > mymatrix[,i] <- myconstant * mymatrix[,i-1] > } > > > Can anyone give me some advice whether it is possible to > avoid this loop > (and if yes: how)? > > Any suggestions are welcome! > > Thanks, > Roland > > > > > +++++ > This mail has been sent through the MPI for Demographic > Rese...{{dropped}} > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html