Hey, Thank you for your swift responses, both options work great.
Aimee On Wed, Jun 15, 2011 at 11:30 PM, Rolf Turner <rolf.tur...@xtra.co.nz>wrote: > On 16/06/11 11:07, Aimee Jones wrote: > >> Hi all, >> My apologies if this message is incredibly inept but I am very new to both >> computer programming and to R. >> >> I am working with the odesolve add-on and have the following function >> defined >> >> RVF_Single<- function(t, x, p) >> within the script I also have the following functions defined: >> >> T1<-function(t) {T1<-27.5-12.5*cos(2*pi*t/365)} >> and >> >> B1<-function(T1,t) {B1<-dnorm(T1(t),mean=22.5,sd=3.3)} >> > > Actually your code should read: > > T1<-function(t) {27.5-12.5*cos(2*pi*t/365)} > > and > > B1<-function(T1,t) {dnorm(T1(t),mean=22.5,sd=3.3)} > > i.e. don't assign the value that you calculate in the code; this > is the value ***returned*** by the function. What you is in effect > harmless here, but it is confusing and could cause problems in > other contexts. > > When the script is run it doesn't return an error message but the graphs >> returned are "wrong". When I input "plot(T1,0,3650)" it returns the plot >> of >> T1 as expected---a series of waves between 15 and 40, BUT when I input >> "plot(B1,0,3650)" I get an error message of "Error in 2 * pi * t : 't' is >> missing". >> >> Can anyone advise as to why t registers for function T1 but disappears for >> function B1? >> > > Well, T1() a function of ***t*** only (where t is the variable against > which > you expect the values of T1() to be plotted. Whereas, B1 is a function of > two variables T1 and t, which confuses things. > > Note that by calling plot() in this way you are in fact calling > plot.function() > which is in fact a wrapper for curve(). As has been discussed recently on > this list, the syntax for curve() is a bit delicate. > > A workaround for your problem is: > > plot(function(t){B1(T1,t)},0,3650) > > HTH > > cheers, > > Rolf Turner > > > > [[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.