[FORGED] Re: draw stripes in a circle in R

On Jun 14, 2017, at 10:18 AM, David Winsemius <dwinsemius at comcast.net> wrote:

On Jun 14, 2017, at 9:46 AM, Jeff Newmiller <jdnewmil at dcn.davis.ca.us> wrote:

I don't see a question. If your question is whether R supports pattern fills, AFAIK it does not. If that is not your question, ask one.
-- 
Sent from my phone. Please excuse my brevity.

On June 14, 2017 7:57:41 AM PDT, jean-philippe <jeanphilippe.fontaine at gssi.infn.it> wrote:

dear R users,

I would like to fill a circle with yellow stripes instead of a uniform
yellow color. To draw the circle I used the following command after
having loaded the (very nice !) plotrix library :

I finally understood the question and it needs a hack to the draw.circle function in plotrix since the angle and density arguments don't get passed in:

First get code for draw.circle:

------

draw.circle?? # then copy to console and edit

draw.circle2? <- function (x, y, radius, nv = 100, border = NULL, col = NA, lty = 1,
???????????????????????????? density=NA, angle=45,? lwd = 1 )
{
????? xylim <- par("usr")
????? plotdim <- par("pin")
????? ymult <- getYmult()
????? angle.inc <- 2 * pi/nv
????? angles <- seq(0, 2 * pi - angle.inc, by = angle.inc)
????? if (length(col) < length(radius))
????????? col <- rep(col, length.out = length(radius))
????? for (circle in 1:length(radius)) {
????????? xv <- cos(angles) * radius[circle] + x
????????? yv <- sin(angles) * radius[circle] * ymult + y
????????? polygon(xv, yv, border = border, col = col, lty = lty, density=density, angle=angle,
????????????????? lwd = lwd)
????? }
????? invisible(list(x = xv, y = yv))
}

Now run your call to pdf with draw.circle2 instead of draw.circle.

Error in alpha("red", 0.4) : could not find function "alpha".