Reputation: 751
For the example given below, how could I paint the area between the dashed lines?
Here is the code:
X <- rnorm(100)
Y<- X + rnorm(100)
reg<-lm(Y~X)
CI <- predict(reg,interval="confidence")
F <- CI[,1]
L <- CI[,2]
U <- CI[,3]
plot(X,F)
abline(reg, col="red")
reg2<-lm(L~X)
abline(reg2, col="red", lty="dashed")
reg3<-lm(U~X)
abline(reg3, col="red", lty="dashed")
here is the output
Upvotes: 4
Views: 1052
Reputation: 263481
Seems like it should be a duplicate but I couldn't find it in an SO search. I know it's appeared many times on rhelp. But there's a fortune for that:
require(fortunes)
fortune("every question")
Lastly, by what we could call the 'Liaw-Baron principle', every question that can be
asked has in fact already been asked.
-- Dirk Eddelbuettel (citing Andy Liaw's and Jonathan Baron's opinion on unique
questions on R-help)
R-help (January 2006)
polygon(x= c(X[order(X)], rev(X[order(X)]) ), # both x and y go "out" in order;
y=c(L[order(X)], rev(U[order(X)])), # and then come "back in reverse order
col=rgb(1,0,0,0.3) ) # transparent pink.
> plot(X,Y, pch="+")
> abline(reg, col="red")
> polygon(x= c(X\[order(X)\], rev(X\[order(X)\]) ), y=c(L\[order(X)\],rev(U\[order(X)\])), col=rgb(1,0,0,0.3) )
Upvotes: 3