Hi all,

First off, thank you for the overwhelming response last time.  I'm still
trying to figure out the syntax of R to plot some distributions of some
frequencies.  I've managed to plot histograms from the data, but I would
like to clean it up using xyplot from library(lattice).  Unfortunately
I cannot find a solution to my problem.

Given a dataframe "all2", with numerical data in cols "year" and "standard"
("standard" being standardized data)

>all2
    Year    standard
1   2001 0.034246575
2   2001 0.000000000
...

141 2008 0.012820513
142 2008 0.230769231


I have plotted separate histograms for each year using
hist(all2[Year==2001,]$standard,breaks=seq(0,.7,.005),ylim=c(0,10),main="2001",xlab="cooccured/total
sites",ylab="frequency of cooccurance")
hist(all2[Year==2002,]$standard, ...
hist(all2[Year==2003,]$standard, ...
etc.

I would like to clean it up a bit by plotting the data using xyplot from
library(lattice) of the standardized.data.

My questions are:

a. Is there a function I could use inside "xyplot" to graph the
frequency/histogram of a given year?

I tried something around the lines of,
xyplot(freq(all2[Year==2001,]$standard)~(all2[Year==2001,]$standard)|all2[Year==2001])
obviously did not work.

b. How would I plot the frequencies of standard for each year in xyplot?

I tried converting all2 into a ftable, and from there converting it into a
dataframe (freqframe) and then plotting:
xyplot(freqframe$Freq~freqframe$standard|freqframe$Year)
the plot is wrong, probably because the dataframe has unnecessary repeats of
values.
I also tried converting all2 into a ftable (also tried a matrix) and naming
the columns and rows and evoking them in the xyplot. But this has also
turned disasterous.

Thanks in advance!

-- 
Lanna Jin

lannajin@gmail.com
510-898-8525

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