R help - Oct 2011 - Create a matrix with increment and element with zero subscript

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?

Thanks,
Deana

Hi Deana,

No, R does not deal with zero subscripts.  Could it be done?  Of
course.  The simplest approach is: 0 + 1 = 1, which is the R
equivalent.  You need to adjust your code to go, for example, from 1
to 30 instead of 0 to 29.

Cheers,

Josh

On Mon, Oct 24, 2011 at 4:23 PM, Md Desa, Zairul Nor Deana Binti
<zndeana at ku.edu> 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?
>
> Thanks,
> Deana
>
> ______________________________________________
> R-help at 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
Programmer Analyst II, ATS Statistical Consulting Group
University of California, Los Angeles
https://joshuawiley.com/

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

Md Desa, Zairul Nor Deana Binti <zndeana <at> ku.edu> writes:
> 
> Hello,
> Does anyone knows how to deal with zero subscript in R. 
  Try the "Oarray" package (that's a capital letter
"O").