[R] radial.plot shaded region

[Jim Lemon]

On 12/11/2013 10:33 AM, Hodge, Steven wrote:
> I'm working with radial.plot in the plotrix package.
>
> Is there a way to show a shaded region for a specific range of values in radial.lim?
>
> For example:
> # test data from radial.plot{plotrix}
> testlen<-c(sin(seq(0,1.98*pi,length=100))+2+rnorm(100)/10)
> testpos<-seq(0,1.98*pi,length=100)
>
> # the original plot
> radial.plot(testlen,testpos,rp.type="p",main="Test Polygon",line.col="blue")
>
> # my attempt to shade the region between 3 and 3.5:
> radial.plot(
> 	matrix(c(3.5, 3), byrow = TRUE),
> 	matrix(c(testpos, testpos), byrow = TRUE, nrow = 2),
> 	rp.type="p",
> 	main="Test Polygon",
> 	poly.col = c('light blue', 'white'),
> 	radial.lim = c(0, 3.5)
> 	)
> # In effect, draw a polygon at 3.5 filled with light blue, then another at 3 filled with white.
> # Now overplot the values of interest:
> radial.plot(testlen,testpos,rp.type="p",main="Test Polygon",line.col="blue", radial.lim = c(0, 3.5), add = TRUE)
>
> Is there an easier way? How can I re-draw the grid lines that are in the original plot?
>
Hi Steve,
That is a tricky one. The best I can do at the moment is to suggest the 
following be added:

radial.grid(radial.lim=c(0,3.5),
  grid.pos=seq(0,3.5,length.out=8))
radial.plot(testlen,testpos,rp.type="p",
  main="",line.col="blue",add=TRUE)

There may be a solution using the radial.pie function, and if I find it, 
I'll post it.

Jim