On 04/04/2013 11:38 AM, Julio Sergio wrote:
To superimpose two functions plots in the same page. The functions L0 and L1, as defined below, I use the following code:# An accumulative normal distribution function with # several parametres f0 <- function(mu, xm, ds, n) { 1 - pnorm((xm-mu)/(ds/sqrt(n))) } f1 <- function(mu,n) f0(mu, 386.8, 48, n) # Two functions with just the parameter mu L0 <- function(mu) f1(mu, 36) L1 <- function(mu) f1(mu,100) plot(L0,ylim=c(0,1),xlim=c(360,420)) curve(L1,add=T) However, I'm puzzled with a problem in the same line: When I passed a "function producer" to plot, again it worked well; however it didn't work in the same way when trying to use this same argument in curve. See what I'm talking about: # A particular normal distribution function: dn8 <- function(z,m) dnorm(z,m,8) # norm dist with sd=8 # A function that produces functions: # returns a function such that given a mean(i) depends only # on z fi <- function(i) function(z) dn8(z,i) plot(fi(370),xlim=c(360,420)) # Works well! curve(fi(380),add=T) # This doesn't work # However, if I put it in this way, surprisingly, it works! ff <- fi(380) curve(ff,add=T) I cannot understand this behaviour. Could anyone give me some feedback on this?
The curve() function is trying to be clever, but it's not. You can probably get what you want using curve(fi(380)(x), add=TRUE). It treats the "x" argument specially.
Duncan Murdoch ______________________________________________ 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.
