[R] problem in ls.ranking.capa.ident mehod

[Hazura Zulzalil]

Hi R-experts,

I apologize for the multiple posting...

My previous post seems to have been eaten by the server because of
embedded code. 

First of all, I am working on Windows XP, using R version 2.6.2. 
<http://2.6.2./>

I got this error message

" Error in drop(.Call("La_dgesv", a, as.matrix(b), tol, PACKAGE = 
"base")) :
  system is computationally singular: reciprocal condition number = 
4.68861e-18


a1 <- c(76.18, 61.84, 60.4, 69.09)
a2 <- c(51.01, 50.39, 87.62, 52.03)
a3 <- c(80.08, 48.49, 90.86, 76.11)
a4 <- c(57.71, 38.99, 88.7, 53.12)
a5 <- c(71.93, 82.04, 83.05, 85.99)
a6 <- c(60.94, 71.12, 63.61, 69.47)

##preference threshold relative
## to the preorder of the alternatives

C<- rbind (a1, a2, a3, a4, a5, a6)
 rk.proto <- rbind (c(5,3), c(3,1), c(1,6), c(6,4), c(4,2))
Asp <-rbind (c(1,2,-delta.S), c(2,1,-delta.S), c(3, 4,-delta.S), c(4, 3, 
-delta.S))
 
## an interaction preorder constraint matrix
delta.I <- 0.05
Aii <- rbind (c(1,2,-1,-delta.I), c(1,3,delta.I, 1), c (1,4,-1,-delta.I),
+ c(2,3, delta.I,1), c(2, 4,-1,-delta.I), c(3,4,delta.I, 1))
 
gls <-ls.ranking.capa.ident(4,2,C, rk.proto,0.5, A.Shapley.preorder = 
Asp, A.interaction.interval = Aii)
Error in drop(.Call("La_dgesv", a, as.matrix(b), tol, PACKAGE = "base")) :

Kindly help me if anyone who has experienced the same problem with me.

Thanks in advance

Hazura