[R] getting lines with non-rounded caps?

[Emmanuel Paradis]

At 11:31 19/09/00 -0700, you wrote:
>I'm trying to get a plot with wide lines that don't have rounded end caps. 
>You can see the effect quite clearly with a plot like this:
>
>plot(0:1)
>lines(c(1.5,1.5),c(0,.5),lwd=20,col="red")
>lines(c(1.5,1.5),c(.5,1),lwd=20,col="green")
>abline(h=0)
>abline(h=0.5)
>abline(h=1)
>
>The colored lines should be between the horizontal lines, but because of the
>rounded end caps, they aren't.
>
>Under X11, if I set lty to something like "F0", the end caps are turned off. 
>Unfortunately, the "0" appears to get ignored, and the line style is the same
>as "FF", i.e. 16 units of drawn line, then 16 units of space.
>
>With the postscript device, lines styles like "FF" still get rounded end
caps,
>unlike X11.

Hi,

This is a behaviour I already noticed under Windows NT when using plot(...,
type="h", lwd=10), so that the thickness of the lines is expanded all
around their starting- and end-points, rather than only perpandicularly to
the lines (which was what I expected). A workaround for the example you
give is to use rect()

 thi <- 0.025
 plot(0:1)
 rect(1.5-thi, 0, 1.5+thi, 0.5, col="red", border="red")
 rect(1.5-thi, 0.5, 1.5+thi, 1, col="green", border="green")
 abline(h=0); abline(h=0.5); abline(h=1)


Emmanuel Paradis
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._