par("uin") ?
Michael,
I have a very old version of some brace functions somewhere.
I never did combine them into a single function, so there's
one each for left/right/up/down braces. (I used them in
teaching regression to show resids and formulae.)
If you're interested, I'll dig 'em up and send them.
Otherwise, I think you can make your inherited code work
with something like
Usr <- par('usr')
Pin <- par('pin')
dux <- Usr[2] - Usr[1]
duy <- Usr[4] - Usr[3]
uin <- c(dux,duy)/Pin
to replace
uin <- par("uin")
But you'll also have to fiddle with atan()
-Peter Ehlers
On 2010-07-19 9:20, Michael Friendly wrote:
I inherited a function written either for an older version of R or SPlus
to draw a brace, "{", in a graph. It uses par("uin") to determine the
scaling of the
quarter circles that make up segments of the brace, but that setting
doesn't
exist in current R.
I'm guessing that, in the function below, ux, uy can be defined from
par("usr") and par("pin"), but maybe someone remembers what par("uin")
was supposed to refer to.
brace <- function (x1 = 0, y1 = 0, x2 = 0, y2 = 1, right = TRUE, rad = 0.2)
{
uin <- par("uin")
ux <- uin[1]
uy <- uin[2]
dx <- x2 - x1
dy <- y2 - y1
alpha <- atan(ux * dx, uy * dy)
scale <- sqrt((ux * dx)^2 + (uy * dy)^2)
if (scale > 5 * rad)
rad <- rad/scale
qcirc <- cbind(cos((0:10) * pi/20), sin((0:10) * pi/20))
qcircr <- cbind(cos((10:0) * pi/20), sin((10:0) * pi/20))
rot <- function(theta) t(cbind(c(cos(theta), sin(theta)),
c(-sin(theta), cos(theta))))
seg1 <- t(t(rad * qcirc %*% rot(-pi/2)) + c(0, rad))
seg4 <- t(t(rad * qcirc) + c(0, 1 - rad))
seg3 <- t(t((rad * qcircr) %*% rot(pi)) + c(2 * rad, 0.5 +
rad))
seg2 <- t(t((rad * qcircr) %*% rot(pi/2)) + c(2 * rad, 0.5 -
rad))
bra <- rbind(seg1, seg2, seg3, seg4)
if (!right)
bra <- bra %*% diag(c(-1, 1))
bra <- scale * bra %*% rot(-alpha)
bra <- bra %*% diag(c(1/ux, 1/uy))
bra <- t(t(bra) + c(x1, y1))
bra
}