hi all assume that one is doing a simulation. in each iteration one produces a vector of results. this vectors length might change for each different iteration. how can one construct a matrix that contains all of the interation results in a matrix where each of the columns are the outputs from the different interations. how would have to define the output matrix initally? / thanking you in advance
Clark Allan wrote:> hi all > > assume that one is doing a simulation. in each iteration one produces a > vector of results. this vectors length might change for each different > iteration. how can one construct a matrix that contains all of the > interation results in a matrix where each of the columns are the outputs > from the different interations. > > how would have to define the output matrix initally?Of course, you define it to the maximal_length x number_iterations, but in fact you probably want a list rather than a matrix. Uwe Ligges> / > thanking you in advance > > > ------------------------------------------------------------------------ > > ______________________________________________ > R-help at 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
1) If the output at each iteration gives a fixed number of elements, then you can pre-define the matrix. For example mat <- matrix( NA, nr=6, nc=500 ) for(i in 1:500 ){ x <- rnorm(13) mat[ , i] <- summary(x) } 2) If the length of the output varies at each iteration, then it is probably best to use a list. mylist <- list(NULL) for(i in 1:500){ x <- rpois(1, lambda=10) + 1 y <- rnorm(x) my.list[[ i ]] <- y } Regards, Adai On Mon, 2005-08-08 at 12:34 +0200, Clark Allan wrote:> hi all > > assume that one is doing a simulation. in each iteration one produces a > vector of results. this vectors length might change for each different > iteration. how can one construct a matrix that contains all of the > interation results in a matrix where each of the columns are the outputs > from the different interations. > > how would have to define the output matrix initally? > > / > thanking you in advance > ______________________________________________ R-help at 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