[R] Plotting multiple ablines

[r at quantide.com]

May be:

plot(c(-1, 1) , c(-1, 1), type = "n")
n = 4
a = rep(0, n)
b = 1:n/n


fun = function(i, a, b, col = 1 , ...) {
    abline(a[i], b[i], col = col[i], ...)
}

lapply(1:n, fun, a=a, b=b, col = 1:n)

Andrea


Thomas Levine wrote:
> I really want to do this:
>
> abline(
> a=tan(-kT*pi/180),
> b=kY-tan(-kT*pi/180)*kX
> )
>
> where kX,kY and kT are vectors of equal length. But I can't do that
> with abline unless I use a loop, and I haven't figured out the least
> unelegant way of writing the loop yet. So is there a way to do this
> without a loop?
>
> Or if I am to resort to the loop, what's the best way of doing it
> considering that I have some missing data? Here's the mess that I
> wrote.
>
> converge <- na.omit(data.frame(kX,kY,kT))
> for (z in (length(converge$kT)))
> {abline(
> a=tan(converge$kT[z]*pi/180),
> b=converge$kY[z]-tan(-converge$kT[z]*converge$kX[z]*pi/180)
> )}
>
> I think the missing data are causing the problem; this happens when I run:
>
> Error in int_abline(a = a, b = b, h = h, v = v, untf = untf, ...) :
>   'a' and 'b' must be finite
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>