Greetings Friends,
I would be grateful if you can help me undestand how to make my R code more
efficiently.
I have read in R intoductory tutorial that a for loop is not used so ofter (and
is not maybe not that efficient) compared to other languages.
So I am trying to build understanding how to get the equivalent of a for loop
using more R-oriented thinking.
If I got it right one way to do that in R is Vectorize. So I have writen a
small snippet of code with two nested for loops. I would be grateful if you can
help me find the equivalent of this code using Vectorize (or any other R
thinking)
My code takes as input a n*m matrix and prints the x,y coordinates where a
cells starts and ends.
remap <- function (sr){
# Input this funcion takes as arguments
# sr: map
startpos<- -1 #
endpos<- +1 #
stepx<- (endpos - (startpos)) / nrow(sr)
stepy<- (endpos - (startpos)) / ncol(sr)
for (i in seq(from=-1,to=1,by=stepx) ) {
for (j in seq(from=-1,to=1,by=stepx) ){
cat(' \n',i,j)
}
}
}
sr<-matrix(data=seq(from=1,to=9),nrow=3,ncol=3,byrow=TRUE)
remap(sr)
Regards
Alex
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