On Sat, 2005-10-08 at 09:28 -0400, Denis Chabot wrote:
Hi,
A few times I tried to control the number and position of tick marks
in plots with the yasp or xasp parameters. For example, a y axis was
drawn by default with tick marks at 0, 20, 40, 80 and 100. I tried to
get tick marks every 10 by adding
yasp=(0, 100, 10)
but this had no effect at all. I know I can draw the axis and tick
marks manually, but often this simple option would suffice if I could
understand how to make it work.
Thanks in advance,
Denis Chabot
I suspect that one problem you are having is that there is no
par("xasp") or par("yasp")....unless these are typos and you are
trying
to use par("xaxp") and par("yaxp")?
There is an 'asp' argument to some of the plot functions (ie.
plot.default), but this has a different intention.
par("xaxp") and par("yaxp") are not listed as read only pars in ?par,
however, I cannot recall an instance where R does not overwrite the
user
settings during the calculation of the axes, whether passed as
arguments
to a plot function or set a priori via a par() call.
If you want explicit control over the tick marks, you will need to use
axis(), perhaps in combination with axTicks(), after using 'xaxt =
"n"'
and/or 'yaxt = "n"' in the plot call, depending upon the
circumstances.
HTH,
Marc Schwartz