[R] problem on pg32 of ISwR

[Gavin Simpson]

On Thu, 2008-02-21 at 11:06 -0500, b.r. clark wrote:
> > hist.with.normal<-function(x,xlab=deparse(substitute(x)),...)+ (+
> h<-hist(x, plot=F, ...)+ s<-sd(x)Error: unexpected symbol
> in:"h<-hist(x, plot=F, ...)s"> 
>  
> I am using ISwR to teach myself R. Above is what happens when I try to
> duplicate the example on page 32. What went wrong? Note: I am using
> shift-enter to advance to the next line.

Don't type the "+". This is R indicating the it is waiting for you to
complete the entry, and it is showing you this by changing the prompt to
a "+".

Type is exactly as you see it, (not the ">" or "+"), so when you get to
the end of a line, hit the return key (don't use shift-return), then
you'll see R change the prompt to a "+".

You also appear to not by typing the braces "{" "}"

So you would type this exactly:

hist.with.normal<-function(x,xlab=deparse(substitute(x)),...)
{
h <- hist(x, plot=FALSE, ...)
s <- sd(x)
m <- mean(x)
ylim <- range(0, h$density, dnorm(0, sd = s))
hist(x, freq = FALSE, ylim = ylim, xlab = xlab)
curve(dnorm(x, m, s), add = TRUE)
}

Then, for example use it like so:

dat <- rlnorm(100)
hist.with.normal(dat)

Does this make sense?

G
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