Dear Jonh, there is probably an easier way, but i find this to give nice smooth plots. good luck with it.
### R-file alive <- data$num - data$numdead numdead <- data$numdead temp <- data$temp data.table <- cbind(numdead, alive) points.graph <- data$alive/data$num glm.mort<-glm(data.table ~ temp, family=binomial) fit <- predict(glm.mort, type='response' ) a <- glm.mort$coef[1] # writes model parameters to named variable, you can also use them directly in a function, as you like b <- glm.mort$coef[2] x2 <- c((logit(fit)-(a))/b) p2 <- c ((inv.logit(a+b*x2)) ) y2 <- c ( a+b*x2) plot(c(30,55), c(0,1),type="n", main= "survival",xlab = "Log x", ylab = "Probability") lines( sortedXyData( (logit(p2)-(a))/b,p2),type="l",lty=1 ,col="blue",ylim=c(0,1.2) ) points(temp,fit,pch=4,type= "p",col="black") ## This will plot a smooth cuve x <- c(x=(rep(33:55,1))) p <- c ((inv.logit(a+b*x)) ) y <- c ( a+b*x) plot(c(30,55), c(0,1),type="n", main= "survival",xlab = "Log x", ylab = "Probability") lines( sortedXyData( (logit(p)-(a))/b,p),type="l",lty=1 ,col="blue",ylim=c(0,1.2) ) points(temp,fit,pch=4,type= "p",col="black") ### END Willems Tom E-mail: [EMAIL PROTECTED] Disclaimer: click here [[alternative HTML version deleted]] ______________________________________________ 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.