I accidentally did not respond to the list. ---------- Forwarded message ---------- From: Abhilash Balakrishnan <balaab...@gmail.com> Date: Sun, Jun 5, 2011 at 8:44 PM Subject: Re: [R] Question about curve function To: Matt Shotwell <m...@biostatmatt.com>
Dear Mr. Shotwell, Thank you for the explanation. You seem to be right. In particular I tried the following: > x <- function(x) { x } > curve(x) Works! So, now x is interpreted as a function, and is plotted accordingly. I also found that this works too: > curve(I) With your explanation I now understand why it works. Thank you for support. Abhilash B. On Sun, Jun 5, 2011 at 1:11 PM, Matt Shotwell <m...@biostatmatt.com> wrote: > I think there is trouble because expr in curve(expr) may be the name of > a function, and it's ambiguous whether 'x' should be interpreted as a > mathematical expression involving x, or the name of a function. Here are > some examples that work: > > curve(I(x)) > curve(1*x) > > On Sun, 2011-06-05 at 12:07 -0500, Abhilash Balakrishnan wrote: > > Dear Sirs, > > > > I am a new user of the R package. When I try to use the curve function > it > > confuses me. > > > > > curve(x^2) > > Works fine. > > > > > curve(x) > > Makes a complaint I don't understand. Why is x^2 valid and x is not? > > > > I check the documentation of curve, and it says the first argument must > be > > an expression containing x. > > > > > expression(x) > > Is an expression containing x. > > > > > curve(expression(x)) > > Makes a different complaint and mentions different lengths of x and y > (but I > > use no y here). > > > > I understand that plotting the function y(x) = x is rather silly, but I > want > > to know what I am doing wrong, for the sake of my understanding of how R > > works. > > > > Thank you for support. > > Abhilash B. > > > > [[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. > > > [[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.