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

[David Winsemius]

> On Jun 14, 2017, at 1:53 PM, Rolf Turner <r.turner at auckland.ac.nz> wrote:
> 
> On 15/06/17 05:29, David Winsemius wrote:
>>> 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.
> 
> This is just idle curiosity, since I'm not really able to contribute anything useful, but I can't resist asking:  When I try to run the OP's code I get an error:
> 
>> Error in alpha("red", 0.4) : could not find function "alpha".
> 
> Why does this (apparently) not happen to anyone else?  Why does the universe pick on *me*?  What is the function "alpha()"?  Where is it to be found?

I discovered some time ago that I no longer needed to load the ggplot2 package. I wasn't entirely happy to make this discovery since I stilll cling to the old lattice style. Eventually I figgured out that it was because one of packages that I load in my .Rprofile-file had changed its imports. The `alpha` function I see is from ggplot2. Resistance is futile. I've now been partially assimilated.


> 
> Searching on "alpha" is of course completely unproductive; there are far too many (totally irrelevant) instances.


> 
> cheers,
> 
> Rolf
> 
> -- 
> Technical Editor ANZJS
> Department of Statistics
> University of Auckland
> Phone: +64-9-373-7599 ext. 88276

David Winsemius
Alameda, CA, USA