Re: [R] Odp: For loops in R

Hi r-help-boun...@r-project.org napsal dne 19.01.2010 02:32:45: > > Hello Petr. > > For the random values, I wanted to generate a different random number for > each element of my velocity matrix. > > So will this do it? > > rmat <- matrix(runif(1000), 500,2) > rmat2 <- matrix(runif(1000), 50

Re: [R] Odp: For loops in R

Hello Petr. For the random values, I wanted to generate a different random number for each element of my velocity matrix. So will this do it? rmat <- matrix(runif(1000), 500,2) rmat2 <- matrix(runif(1000), 500,2) rindex <- sample(1:500, replace=TRUE) #with repetition velocity<-0.4 * velocity +

Re: [R] Odp: For loops in R

Hi slightly better. However it would be nice if you provided some code which works but not the way you want. Loops are not as problematic but often you achieve far better results by avoiding them and using vectorised code. Still there are some oddities. random values in formula below shall be

Re: [R] Odp: For loops in R

Hello Sorry for the confusion Here are additional details. velocity, popVar, archiveVar,pbestsVar are matrices with dimension of 500 row, 2 col matrix. I want to assign new values for each velocity[i,j] using the formula below: *0.4 * velocity[i,j] + 1 * randomvalue * (pbestsVar[i,j] - popVar[

[R] Odp: For loops in R

Hi Definitely not from first I get > gBest<-floor(runif(popsize,min=1,max=top)) Error in runif(popsize, min = 1, max = top) : object 'popsize' not found > and from second > for (i in 1:popsize) { + for (j in 1:maxvar) { +gBest<-sample(top,size=1) +velocity[i,j]<<-.4* velocity[i,j]