I've spent quite a lot of the day trying to construct a fairly
standard line plot in R, and I have the feeling there is a simple way
that I haven't discovered.
I have a large vector of measurements (TIME), and each measurement
falls into one of three categories (PHASE). For each PHASE value, I
want a mean of the corresponding TIME measurements plotted as a point
along with standard error bars. I'd like the three resulting point
connected with line segments.
I'd like to have two data series like this plotted on the same graph
-- one in red, one in blue.
Excel, as awful as it is, does this kind of graph quite easily.
After sifting through the scattered documentation, the best I could
do was to store the mean values of the three points, plot those three
numbers against the values 1,2, and 3, then use the arrows() function
to draw error bars on each one. This is a LOT of manual effort, as
you can imagine (in addition to the means I have to calculate the
standard errors for each point, and I still don't know how to draw
each of the three line segments I need).
Any suggestions?
Thanks,
--Ashish.
-----
Ashish Ranpura
Institute of Cognitive Neuroscience
University College London
17 Queen Square
LONDON WC1N 3AR