[R] Residual plotting

[wildscop]

Dear all,

So far i could do (in an informal way) to draw a Standardized Resisual plot 
in the following way-
---------------------
 >x <- c(104.1, 106.6, 105.5, 107.5, 109.6, 113.3, 115.5, 117.7, 119.9, 
122.1, 124.3, 126.5, 128.2)
 >y <- c(53732, 52912, 57005, 61354, 67682, 71602, 71961, 75309, 82931, 
93310, 102161, 103068, 108927)
 > beta1<-(n*sum(x*y)-sum(x)*sum(y))/(n*sum(x^2)-sum(x)^2)
 > beta0<-sum(y)/n-beta1*sum(x)/n
 > yhat<-beta0 + beta1*x
 > error<-(y-yhat)
 > se <- sqrt((sum(y^2)-beta0*sum(y)-beta1*sum(x*y))/(n-2))
 > SE<-sqrt(sum(error^2)/(n-2)) # just another way
 > plot(x,error)
 > plot(x,error/se)
---------------------
Or, in the formal way (using s-plus functions), in the following way, but i 
get stuck in the Resisual plot stage, don't know how to draw the 
"Standardized Resisual plot" in this way :

---------------------
 >x <- c(104.1, 106.6, 105.5, 107.5, 109.6, 113.3, 115.5, 117.7, 119.9, 
122.1, 124.3, 126.5, 128.2)
 >y <- c(53732, 52912, 57005, 61354, 67682, 71602, 71961, 75309, 82931, 
93310, 102161, 103068, 108927)
 > cripop<-rbind(x,y)
 > dimnames(cripop)<-NULL
 > columns <- c("1987", "1988", "1989", "1990", "1991", "1992", "1993", 
"1994", "1995", "1996", "1997", "1998", "1999" )
 > rows<-c("Population","Crimes")
 > dimnames(cripop)<-list(rows,columns)
 > bd<-t(cripop)
 > bd.frame<-data.frame(bd)
 > attach(bd.frame)
 > regressions<-lm(Crimes~Population,data=bd.frame)
 > plot(Population,resid(regressions))
 > ...?...
---------------------
Can any one help me by telling me how can i draw "Standardized Resisual 
plot" from here ?

Also, is there any way i can construct 95% Confidence interval or 
Prediction interval for any value in R ?

_______________________

Mohammad Ehsanul Karim <appstat at HotPOP.com>
Institute of Statistical Research and Training
University of Dhaka, Dhaka- 1000, Bangladesh
_______________________


_______________________

Mohammad Ehsanul Karim <appstat at HotPOP.com>
Institute of Statistical Research and Training
University of Dhaka, Dhaka- 1000, Bangladesh