[R] draw stripes in a circle in R

[David Winsemius]

> 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 :
>> 
>> library(plotrix)
>> pdf("MWE.pdf",width=8, height=8)
>> plot(seq(-12.5,-8.7,length.out=100),seq(-11.3,-8.3,length.out=100),type="l",col="red",xlim=c(-12.5,-8.7),ylim=c(-11.5,-8.5))
>> par(new=T)
>> plot(seq(-12.5,-8.7,length.out=100),seq(-11.7,-8.7,length.out=100),type="l",col="red",xlim=c(-12.5,-8.7),ylim=c(-11.5,-8.5))
>> par(new=T)
>> polygon(c(seq(-12.5,-8.7,length.out=100), 
>> rev(seq(-12.5,-8.7,length.out=100))), c(seq(-11.3,-8.3,length.out=100),
>> 
>> rev(seq(-11.7,-8.7,length.out=100))),
>>        col = alpha("red",0.4), border = NA)
>> par(new=T)
>> draw.circle(-12.85,-10.9,0.85,nv=1000,border=NULL,col="yellow",lty=1,lwd=1)
>> dev.off()
>> 

Agree that the coding question remains unclear, so not using the offered example but responding to the natural language query. The `polygon` function has 'density' and 'angle' argument that with 'col' and 'lwd' can make slanted fill lines. This is a modification of hte first example on `?polygon`?

x <- c(1:9, 8:1)
y <- c(1, 2*(5:3), 2, -1, 17, 9, 8, 2:9)
op <- par(mfcol = c(3, 1))
for(xpd in c(FALSE, TRUE, NA)) {
    plot(1:10, main = paste("xpd =", xpd))
    box("figure", col = "pink", lwd = 3)
    polygon(x, y, xpd = xpd, col = "orange", density=3, angle=45,  lwd = 5, border = "red")
}

The polygon function is _not_ in pkg::plotrix.



>> It looks a bit ugly since they are not real data, but it is the
>> simplest 
>> MWE example that I found.
>> 
>> 
>> Thanks, best
>> 
>> 
>> Jean-Philippe
> 
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David Winsemius
Alameda, CA, USA