ifelse help?
On Mon, Jan 19, 2009 at 9:08 PM, <rkevinburton at charter.net> wrote:
Sorry I didn't give the proper initialization of j. But you are right j should also be an array of 5. So x[j + 5] would return 5 values. So if the array returned from 'ifelse' is the same dimention as test (h), then are all the values of h being tested? So since h as you say has no dimensions is the test only testing h[1]? Again it seems that if all of the elements of h are tested (there are 5 elements) and each element produces an array of 5 the resulting array should be 25. Kevin
ifelse returns values "row-by-row", so to speak. in this case, it will return the vector: c(x[j+2][1] , x[j+2][2] , x[j+2][3] , x[j+2][4] , x[j+2][5]). If you instead write: h<-numeric(5) j<-1:5 p <- 1:5 x<-1:1000 ifelse(h == 0,list(x[j+2]), 1:5) ,you get what you expected, since ifelse recycles the second argument if necessary. Regards, Gustaf
Gustaf Rydevik, M.Sci. tel: +46(0)703 051 451 address:Essingetorget 40,112 66 Stockholm, SE skype:gustaf_rydevik