[R] Optimization Hi, I would like to minimize the value of x1-x2, x2 is a fixed value of 0.01, x1 is the quantile of normal distribution (0.0032,x) with probability of 0.7, and the changing value should be x. Initial value for x is 0.0207. I am using the following codes, but it does not work. fr <- function(x) {       x1<-qnorm(0.7,0.0032,x)       x2=0.01       x1-x2 } xsd <- optim(0.0207, fr, NULL,method="BFGS") It is the first time I am trying to use optimization. Could anyone give me some advice? --  View this message in context: http://www.nabble.com/Optimization-tf3941212.html#a11178663 Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@stat.math.ethz.ch 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.