[R] ggplot2 directional line type?

[baptiste auguie]

Hi,

You could add arrows with geom_segment; however if you want even
spacing along the path it might get tricky,


library(ggplot2)

d <- data.frame(x=seq(0, 10, length=100),
                y=sin(seq(0, 10, length=100)))

N <- 10
dN <- 2

ind <- seq(1,nrow(d),by=N)
ind <- ind[-c(1,length(ind))]

d3 <- data.frame(xstart = d$x[ind],
                 xend = d$x[ind+2],
                 ystart = d$y[ind],
                 yend = d$y[ind+2])

ggplot(d)+
  geom_path(aes(x,y)) +
  geom_segment(data=d3, aes(xstart,ystart,xend=xend,yend=yend), arrow=arrow())

HTH,

baptiste

On 23 February 2011 02:00, Malcolm Ryan <malcolmr at cse.unsw.edu.au> wrote:
> I'm doing a path plot with ggplot2, the result is looking very nice, but I want to give some indication of which direction the lines are going. I thought of using colour gradients, but it doesn't look right. What would be ideal is a line type that indicated direction, something like ">>>>>>>". Is there any way to achieve this? Or can anyone suggest another way of representing this information?
>
> Malcolm
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