optimize
On Jan 3, 2011, at 9:52 AM, Muhammad Rahiz 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?
Extend the appropriate axes. xlim and ylim are the arguments to use. Looks too much like a homework problem for me to do the work for you, though.
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)
David Winsemius, MD West Hartford, CT