On 27/04/2009 5:23 PM, Christophe Dutang wrote:
so it could be a limitation of graphics on windows?
It's not graphics on Windows, but it appears to be a limitation of
the windows() graphics device in R. It is used for bitmap plots as
well as on-screen plots, which is why you saw the same effect in
jpeg, but different devices are used for Postscript and PDF.
When drawing lines, R handles the dash style itself, rather than
using the built-in dashes. But it doesn't do so for circles, and
doesn't make use of the Windows line styles.
If you really need the dashes onscreen, you can draw the circle
yourself. Assuming the scales are equal on both axes that's easy,
just use
theta <- seq(0,2*pi, len=256)
lines(x+r*cos(theta), y+r*sin(theta), lty="dashed")
(where (x,y) is the center and r is the radius). It's more work if
you want things to appear as circles when the scales are unequal,
but I think this works:
circle <- function(x, y, inches=1, ...) {
theta <- seq(0, 2*pi, len=256)
lines(x + grconvertX(inches*cos(theta), "inches", "user") -
grconvertX(0, "inches", "user"),
y + grconvertY(inches*sin(theta), "inches", "user") -
grconvertY(0, "inches", "user"),
...)
}
so you'd get the plot you wanted using
circle(0, 0, inches = 1.5, fg="black",lty="dashed")
The circle function is not vectorized, so it's not as useful as
symbols, but it could be improved.
Duncan Murdoch
It also appears with "long dash" lines.
x <- -4:4
y <- -4:4
plot(x,y,type="n")
symbols(0, 0, add = TRUE, circles = 1, inches = 1, fg="black",
lty="solid")
symbols(0, 0, add = TRUE, circles = 1, inches = 2,
fg="black",lty="dashed")
symbols(0, 0, add = TRUE, circles = 1, inches = 3,
fg="black",lty="longdash", lwd=2)
Le 27 avr. 09 ? 23:07, Joshua Wiley a ?crit :
I read that the lty=2 argument does not work on all graphics
devices. You might double check that since it works on mac.
Joshua Wiley
---- Original message ----
Date: Mon, 27 Apr 2009 22:58:11 +0200
From: Christophe Dutang <dutangc at gmail.com>
Subject: Re: [R] problem with symbol function
To: Joshua Wiley <jwile004 at ucr.edu>
Cc: r-help at r-project.org
This point is ok if I download R from the Austrian mirror. R is
properly install on both computers. I also get this strange
behavior
with R 2.7.2. There is something I'm missing...
Le 27 avr. 09 ? 22:54, Joshua Wiley a ?crit :
I am running SP3. You said earlier that you were having trouble
downloading 2.9.0, are you sure everything downloaded and
installed
properly? There have been some questions about transitioning to
the
new build going around.
Joshua Wiley
---- Original message ----
Date: Mon, 27 Apr 2009 22:45:26 +0200
From: Christophe Dutang <dutangc at gmail.com>
Subject: Re: [R] problem with symbol function
To: Joshua Wiley <jwile004 at ucr.edu>
Cc: r-help at r-project.org
what is your service pack version?
at home I use the SP2 version.
Le 27 avr. 09 ? 22:29, Joshua Wiley a ?crit :
Hi Christophe,
I am able to plot dashed circles on Windows. I'm afraid I do not
have any suggestions for you. What happens when you try to
plot it
on Windows?
Joshua Wiley
---- Original message ----
Date: Mon, 27 Apr 2009 22:15:53 +0200
From: r-help-bounces at r-project.org (on behalf of Christophe
Dutang <dutangc at gmail.com
Subject: [R] problem with symbol function
To: r-help at r-project.org
Hi all,
I use the symbol functions to draw circles. But the argument
lty
does
not work on windows but works correctly on my macbook:
x <- -4:4
y <- -4:4
plot(x,y,type="n")
symbols(0, 0, add = TRUE, circles = 1, inches = 1, fg="black",
lty="solid")
symbols(0, 0, add = TRUE, circles = 1, inches = 2, fg="black",
lty="dashed")
The second circle should be drawn with dash... it works on my
macbook
but on my PC.
I use R 2.9.0 on windows xp home and mac os 10.5.
Does anyone have this problem? is it a limitation of windows?
thanks in advance
Christophe
--
Christophe Dutang
Ph. D. student at ISFA, Lyon, France
website: http://dutangc.free.fr
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