R version 2.13.0 (2011-04-13)
Copyright (C) 2011 The R Foundation for Statistical Computing
ISBN 3-900051-07-0
Platform: i486-pc-linux-gnu (32-bit)

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> x <- array(list('T',0,'T',0,'T',1,'T',0,'T',0,'T',0,'T',0,'T',1,'T',1,'T',0,'T',0,'T',1,'T',1,'T',1,'T',0,'T',0,'T',0,'T',0,'T',1,'T',0,'T',0,'T',0,'T',0,'T',-1,'T',0,'T',-1,'T',0,'T',0,'T',0,'T',0,'T',-1,'T',0,'T',0,'T',0,'T',0,'T',0,'T',0),dim=c(2,37),dimnames=list(c('treatment','post-pre'),1:37))
>  y <- array(NA,dim=c(2,37),dimnames=list(c('treatment','post-pre'),1:37))
>  for (i in 1:dim(x)[1])
+  {
+  	for (j in 1:dim(x)[2])
+  	{
+  		y[i,j] <- as.numeric(x[i,j])
+  	}
+  }
There were 37 warnings (use warnings() to see them)
> par3 = 'TRUE'
> par2 = '2'
> par1 = '1'
> ylab = 'Y Variable Name'
> xlab = 'X Variable Name'
> main = 'Title Goes Here'
> cat1 <- as.numeric(par1) #
> cat2<- as.numeric(par2) #
> intercept<-as.logical(par3)
> x <- t(x)
> x1<-as.numeric(x[,cat1])
There were 37 warnings (use warnings() to see them)
> f1<-as.character(x[,cat2])
> xdf<-data.frame(x1,f1)
> (V1<-dimnames(y)[[1]][cat1])
[1] "treatment"
> (V2<-dimnames(y)[[1]][cat2])
[1] "post-pre"
> names(xdf)<-c('Response', 'Treatment')
> if(intercept == FALSE) (lmxdf<-lm(Response ~ Treatment - 1, data = xdf) ) else (lmxdf<-lm(Response ~ Treatment, data = xdf) )
Error in `contrasts<-`(`*tmp*`, value = "contr.treatment") : 
  contrasts can be applied only to factors with 2 or more levels
Calls: lm ... model.matrix -> model.matrix.default -> contrasts<-
Execution halted