Hi all, In the following code, I am trying to use uniroot function to solve for the root (a and b in code below) for function f1. I am not sure why uniroot function does not give the answer since when we look the graph, the function does cross 0 twice. Any suggestion? Thanks. Hanna
u1 <- -3 u2 <- 4 pi0 <- 0.8 f1 <- function(lambda,z,p1){ lambda*(p1*exp(u1*z-u1^2/2)+(0.2-p1)*exp(u2*z-u2^2/2))-(1-lambda)*pi0} a <- uniroot(f1, lower =-10, upper = 0, tol = 1e-20,p1=0.15,lambda=0.998)$root b <- uniroot(f1, lower =0, upper = 10, tol = 1e-20,p1=0.15,lambda=0.998)$root x <- seq(-20,20, by=0.1) y <- numeric(length(x)) for (i in 1:length(x)){y[i] <- f1(x[i],p1=0.15,lambda=0.998)} plot(y ~ x, ylim=c(-1,1)) abline(h=0) [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.