[Rd] can't plot a line

[Prof Brian Ripley]

On Tue, 23 Jan 2007, Spencer Graves wrote:

> Consider the following:
>
>      plot(0, 0, xlim=c(-10, 10), ylim=c(-50, 50))
>      lines(c(0,0), (2*c(-pi, pi))^2)
>
>      I see no line in this plot.

I do. You are drawing a line from a point to itself.  Try lwd=5 and it 
will be more visible.

>
> R version 2.4.1 (2006-12-18)
> i386-pc-mingw32
>
> locale:
> LC_COLLATE=English_United States.1252;LC_CTYPE=English_United
> States.1252;LC_MONETARY=English_United
> States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252
>
> attached base packages:
> [1] "stats"     "graphics"  "grDevices" "utils"     "datasets"  "methods"
> [7] "base"
>
>      My work around is the following:
>
>      pi2.2 <- (2*pi)^2
>      lines(c(0, 0), c(-pi2.2, pi2.2))

What is (-1)^2?

>      Why won't "lines(c(0,0), (2*c(-pi, pi))^2)" work for me?
>      Thanks,
>      Spencer Graves
>
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>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
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