How can I draw the contour of a segment

Question

I am using the R function segments and would like to know how I can draw "around" the segment (the contour), in say black.

plot(0)
segments(.9,.1,.8,.3, lwd=10, lend='square', col='pink')

Here I would get a black rectangle around the pink segment enter image description here

segments are pieces of lines. Hence they have no 'outline'. Use polygon() to get what you want. — Thierry, Aug 14 '13 at 14:27
You can draw it twice, first in black, large (`lwd=12`), then in pink, smaller (`lwd=10`). — Vincent Zoonekynd, Aug 14 '13 at 14:40

score 1 · Accepted Answer · answered Aug 14 '13 at 16:32

1

You can draw it twice, first in black, large (lwd=12), then in pink, smaller (lwd=10).

plot(0)
segments(.9,.1,.8,.3, lwd=12, lend='square', col='black')
segments(.9,.1,.8,.3, lwd=10, lend='square', col='pink')

answered Aug 14 '13 at 16:32

Vincent Zoonekynd

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score 0 · Answer 2 · answered Aug 14 '13 at 15:14

This is pretty messy, but I threw it together anyway.

draw.rect <- function(x1=0.9,y1=0.1,x2=0.8,y2=0.3,width=0.05){
  ang <- atan((y2-y1)/(x2-x1))
  xshift <- width*sin(ang)
  yshift <- width*cos(ang)
  polygon(x=c(x1,x2,x2-xshift,x1-xshift),y=c(y1,y2,y2+yshift,y1+yshift),col="pink")
}

It would allow you to use your same coordinates. You can adjust the size of the rectangle with the width argument. I think @VincentZoonekynd has a great idea with drawing the segment twice. This rough function does not center the rectangle on the coordinates provided, although you could pretty easily adjust it to do so.

How can I draw the contour of a segment

2 Answers2