Hi, I would also like to point out that you flipped the first two the values of theta in the R vs. FORTRAN versions. This fixes part of your differences (and makes it easy to see that the differences occur when j < i, as David and Mario point out).
Josh On Sun, Aug 29, 2010 at 10:27 PM, Nam Lethanh <namkyo...@gmail.com> wrote: > Dear Guys, > > I do converting codes from Fortran into R and got stuck in solving LOOPING > procedure with R. In FORTRAN, it is (DO and END DO) for looping in the net. > In R, it is (FOR with { }). > > I believe there is something wrong with my coding in R, do hope that you can > help me solving following problems. > > It seems easy, but results are not the same. > > *************************************************************************** > WITH R > > theta<-c(0.08,0.06,0.09,0) > for (i in 1:4){ > for (j in 1:4){ > a<-1.0 > for (k in i:(j-1)){ > a<-a*theta[k] > } > print(a) > } > -------------------------------------------------------------------------------------- > HERE GOES the results > ------------------------- > numeric(0) > [1] 0.08 > [1] 0.0048 > [1] 0.000432 > numeric(0) > [1] 0.0048 > [1] 0.06 > [1] 0.0054 > numeric(0) > [1] 0.000432 > [1] 0.0054 > [1] 0.09 > numeric(0) > [1] 0 > [1] 0 > [1] 0 > ********************************************************************************* > IN FORTRAN, the results is totally different. > > program calculating_a > implicit none > integer i, j, k > double precision a, theta(4) > theta(1)=0.06; theta(2)=0.08; theta(3)=0.09; theta(4)=0 > do i=1, 4 > do j=1, 4 > a=1 > do k=i,j-1 > a=a*theta(k) > end do > > print*, a > > end do > end do > end > > Here goes the results with FOTRAN > > ------------------------------------------------------------------------------------- > 1 > 0.06 > 4.79E-003 > 4.31E-004 > 1 > 1 > 0.08 > 7.2E-0.03 > 1 > 1 > 1 > 0.09 > 1 > 1 > 1 > 1 > ----------------------------------------------------------------------------- > > > > Thank you! > > > > Nam > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > -- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.com/ ______________________________________________ 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.