[R] png and pdf : point size, font size, etc.

[Stephan Ripke]

Hi,
I am new to this mailing list. Didn`t find the answer in the archives. But I
guess, there are people out there, who know the solution:
In an automatic script, I want to produce simple plots. First I prefer pdf,
because of scalability and standardization. But when I have too many
datapoints (say 300.000) the viewing and printing is very, very slow. So I
decided to take some bitmapped format when passing 5.000 datapoints, because
most of them are in one cloud. As a result, the png is nice and fast to
handle and in Linux it is very easy to convert it to pdf with imagemagick.
So far so good. The problem is, that the font size and the point-size of the
plotpoints and the all of the plot is getting much smaller when using
png-format. Why is this and how can I circumvent this issue?
These are the two devices, I am opening for the two reasons:

1)
pdf("name_out.pdf",11,3.5)
2)
bitmap("name_out.png",height=3.5,width=11)

all should be the same, isn`t it?

Thanks in advance,
Stephan

-- 
Dr. med. Stephan Ripke
Stat.2 (Neurology)
Max-Planck-Institute of Psychiatry
AG Statistical Genetics
Kraepelinstr. 10
80804 Munich - Germany
Tel. +49 (0)89 30622-422 or -384
Fax. +49 (0)89 30622-610
Email: ripke at mpipsykl.mpg.de