On Oct 24, 2011, at 7:23 PM, Md Desa, Zairul Nor Deana Binti wrote:

Hello,
Does anyone knows how to deal with zero subscript in R. I have this code:
for (i in 1:nitems){
+             for (j in 1:ncat-1)  {
+ draw<-matrix(rnorm(nitems*(ncat-1),seed1,seed2),nitems, (ncat-1))
+          d<-( sigma_d*draw ) + mu_d
+ draw<-matrix(rtnorm((nitems*(ncat-1)),mean = seed1, sd = seed2, lower = .1, upper = 1.5),nitems,(ncat-1))
+           d<-(sigma_d*draw) + mu_d
+ write.matrix(cbind(b.i0,d), file = "F:/KU/MIRT group/ MIMIC-DIF/R/cpprcode/b0d.dat", sep = " ")
+             b[i,j]<-b[i,j-1]+d[i,j]
+                }
+             }

The error as following:

Error in b[i, j ] <- b[i, j - 1] + d[i, j] :
 replacement has length zero

I would like to to have a matrix where the first column takes from initial pre-assigned value (b[i,0]+d1), the second column is additive from the first column and a constant d2 that is (b(i,1)=b(i, 0)+d1+d2, and so forth. Is there any way that R can read subscript of zero?

I don't. (I seem to remember the Matrix package allows such shenanigans.)

Why don't you instead augment b[,] with a top column of initial values, using rbind() and then iterate from 2:(ncat-2). (Do note the parentheses and if you do not know why, then consult ?Syntax for operatr precendence.)

--
David Winsemius, MD
West Hartford, CT

______________________________________________
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.

Reply via email to