Hi, you can use the curve() function for this. It is dedicated to plotting functions.
Here is an example # turn your functions into r functions f <- function(x) 0.25 * x^2 + 6.47 * x -32.6 g <- function(x) 0.99*x^2 -6*x -195 j <- function(x) 0.77*x^2 + 14*x -495 k <- function(x) 0.001*x^2 + 65*x -785 l <- function(x) 0.9*x^2 -2*x -636 # plot f and g curve(f, from=0, to=100, lty=1) curve(g, add=TRUE, lty=2) In this example, the parameters 'from' and 'to' define the domain over wich all functions will be evaluated. The parameter add=TRUE is used to add the second function to the previous plot. HTH Matthieu Matthieu Dubois Post-doctoral fellow, Psychology Department, Univeristé Libre de Bruxelles ______________________________________________ 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.
