Hi Mohamed,
mohamed nur anisah wrote (8.2.2008):
> Dear lists,
>
> I'm in my process of learning of writing a function. I tried to
> write a simple functions of a matrix and a vector. Here are the
> codes:
>
> mm<-function(m,n){ #matrix function
> w<-matrix(nrow=m, ncol=n)
> for(i in 1:m){
> for(j in 1:n){
> w[i,j]=i+j
> }
> }
> return(w[i,j])
> }
This returns the value in row i, in column j, not the matrix.
Replace 'return(w[i,k]) with just 'w'.
> v<-function(n){ #function of a vector
> y=vector(length=n)
> for(i in 1:n){
> y[i]=i
> }
> return(y[i])
> }
The same here: the function returns the value of the ith element in the
vector. Again: Replace 'return(y[i]) with just 'y'.
Please compare the outputs:
> mm<-function(m,n) {
+ w<-matrix(nrow=m, ncol=n)
+ for(i in 1:m) {
+ for(j in 1:n) {
+ w[i,j]=i+j
+ }
+ }
+ return(w[i,j])
+ }
> mm(5,10)
[1] 15
> mm<-function(m,n) {
+ w<-matrix(nrow=m, ncol=n)
+ for(i in 1:m) {
+ for(j in 1:n) {
+ w[i,j]=i+j
+ }
+ }
+ w
+ }
> mm(5,10)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 2 3 4 5 6 7 8 9 10 11
[2,] 3 4 5 6 7 8 9 10 11 12
[3,] 4 5 6 7 8 9 10 11 12 13
[4,] 5 6 7 8 9 10 11 12 13 14
[5,] 6 7 8 9 10 11 12 13 14 15
Kind regards,
Kimmo
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
