[R] multiple plots using a loop

[Darcy Webber]

Dear R users,

I am trying to write myself a loop in order to produce a set of 20
length frequency plots each pertaining to a factor level. I would like
each of these plots to be available on the same figure, so I have used
par(mfrow = c(4, 5)). However, when I run my loop below, it produces
20 plots for each factor level and only displays the last factor
levels LF plots. I'm fairly new to loops in R, so any help would be
greatly appreciated.

I have provided an example data set below if required with just 4
factors and adjusted par settings accordingly.

Factor <- rep(factor(letters[1:4]), each = 10)
Size <- runif(40) * 100

par(mfrow = c(2, 2))

for (i in Factor) {
LFchart <- hist(Size[Factor == i], main = i,
xlab = c("n =",length(Size[Factor == i])), ylab = "")
}

P.S. Also just a quick annoying question. My xlab displays:
n =
120
I would like it to display:
n = 120
but just cant get it to work. Any thoughts.

Regar