Hi Muhammad, On Mon, Jan 3, 2011 at 6:52 AM, Muhammad Rahiz <muhammad.ra...@ouce.ox.ac.uk> wrote: > Hi all, > > I'm trying to get the value of y when x=203 by using the intersect of three > curves. The horizontal curve does not meet with the other two. How can I > rectify the code below?
What is your code supposed to do? This is one way to get three intersecting curves, but I am not sure it is doing what you were hoping to do with the sample code you sent. ts <- seq(200, 209, 1) dd <- c(NA,NA,NA,NA,1.87,1.83,1.86,NA,1.95,1.96) xy <- lm(dd ~ ts) plot(x = ts, y = dd, ylim = c(1.5,2)) abline(xy, col = "blue", lty = 2) abline(v = 203, h = predict(xy, data.frame(ts = 203)), col = "blue", lty = 2) Best regards, Josh > > Thanks > > Muhammad > > ts <- 1:10 > dd <- 10:1 > > ts <- seq(200,209,1) > dd <- c(NA,NA,NA,NA,1.87,1.83,1.86,NA,1.95,1.96) > > plot(ts,dd,ylim=c(1.5,2)) > abline(lm(dd~ts),col="blue",lty=2) > abline(v=203,col="blue",lty=2) > > xy <- lm(dd~ts) > fc <- function(x) coef(xy)[1] + x*coef(xy)[2] > val <- optimize(f=function(x) abs(fc(x)-203),c(1.5,2)) > abline(h=val,col="blue",lty=2) > > ______________________________________________ > R-help@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 University of California, Los Angeles http://www.joshuawiley.com/ ______________________________________________ R-help@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.
