Peng Yu wrote:
On Sun, Oct 18, 2009 at 10:26 PM, Richard M. Heiberger r...@temple.edu
wrote:
points(x[4,],pch=2)# this is plotted as two points
drops what it sees as an unnecessary dimension.
Use
points(x[4,, drop=FALSE], pch=2)
See FAQ 7.5
tmp - matrix(1:2)
tmp
tmp[,1]
tmp[,1,drop=FALSE]
Can I specify 'drop' to FALSE by default so that I don't have to
specify it explicitly?
Not that I know of, but things will be easier with the following idiom:
x = cbind(1:4,3:6)
plot(x[,1],x[,2],pch=rep(1:2,c(3,1)))
even easier if the plot types correspond to a factor variable in
a data frame:
dat = data.frame(x=1:4,y=3:6,type=factor(c(1,1,1,2)))
with(dat,plot(x,y,pch=as.numeric(type)))
To answer one of your other questions: ggplot (and lattice) is/are
very powerful, but base graphics are (a) easier to get your head around
and (b) easier to adjust if you don't like the defaults. Changing things
just a little bit in ggplot can be difficult (as an example, the answer to
your other question about getting rid of grid lines has to do with
theme_blank(), something like +options(grid.panel.minor=theme_blank())
[try googling theme_blank for a few examples])
--
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