Dear Mr. Murdoch, I find out that still do not understand why the following does not work:
> curve(expression(x)) Error in xy.coords(x, y, xlabel, ylabel, log) : 'x' and 'y' lengths differ As here the input to curve is an expression, as documented in the help, and the expression is simply x. What is the y mentioned in the error? There is no y used here. Thank you for support. Abhilash B. On Sun, Jun 5, 2011 at 3:39 PM, Duncan Murdoch <murdoch.dun...@gmail.com>wrote: > On 11-06-05 1:07 PM, 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? >> > > curve() is a convenience function, and it tries to guess what you mean. > Sometimes it gets it wrong. > > In the first case, it is clear you want to graph x^2. In the second it > guesses you have a function named x and want to graph that. You don't, so > it fails. > > Probably it could try again after the first failure, but I'd guess there > will always be strange cases where it does weird things. > > Duncan Murdoch > > >> 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.
