R help - Jun 2009 - Automatically placing a legend in an area with the most white space...

At one point I believe I heard of an R package that would automatically find the
most empty space in a plot, and then that answer could then be used to
intelligently place a legend.

I would like to try to apply that R package to the contrived example shown
below, so thank you for any hints or tips that can be provided.

x = seq(0, 1000, by = 1)
y1_vals<-rnorm(1000, mean = 0, sd = 50)
y2_vals<-rnorm(1000, mean = 25, sd = 40)
y3_vals<-rnorm(1000, mean = 115, sd = 40)

plot(x_vals, y1_vals, pch=22, col="dark red", bg = "dark
red", cex =0.3)
points(x_vals, y2_vals, pch=22, col="dark blue", bg = "dark
blue", cex =0.3)
points(x_vals, y3_vals, pch=22, col="dark green", bg = "dark
green", cex =0.3)

abline(h=0, col="dark red", lwd=1.5, lty=6)
abline(h=25, col="dark blue", lwd=1.5, lty=6)
abline(h=115, col="dark green", lwd=1.5, lty=6)

legend("topright", c("Best Guess 1" , "Best Guess
2", "Best Guess 3"), bg="white", lwd = 2, title =
"Randomness:")

Jason Rupert wrote:
> At one point I believe I heard of an R package that would automatically
find the most empty space in a plot, and then that answer could then be used to
intelligently place a legend.
>
> I would like to try to apply that R package to the contrived example shown
below, so thank you for any hints or tips that can be provided.
>
> x = seq(0, 1000, by = 1)
> y1_vals<-rnorm(1000, mean = 0, sd = 50)
> y2_vals<-rnorm(1000, mean = 25, sd = 40)
> y3_vals<-rnorm(1000, mean = 115, sd = 40)
>
> plot(x_vals, y1_vals, pch=22, col="dark red", bg = "dark
red", cex =0.3)
> points(x_vals, y2_vals, pch=22, col="dark blue", bg = "dark
blue", cex =0.3)
> points(x_vals, y3_vals, pch=22, col="dark green", bg = "dark
green", cex =0.3)
>
> abline(h=0, col="dark red", lwd=1.5, lty=6)
> abline(h=25, col="dark blue", lwd=1.5, lty=6)
> abline(h=115, col="dark green", lwd=1.5, lty=6)
>
> legend("topright", c("Best Guess 1" , "Best Guess
2", "Best Guess 3"), bg="white", lwd = 2, title =
"Randomness:")
>
>   
Hi Jason,
The good news is that the emptyspace function found the largest empty 
space in the plot. The bad news is that there was not nearly enough 
space to fit the legend:

legend(emptyspace(rep(x_vals,3),c(y1_vals,y2_vals,y3_vals)),
  c("Best Guess 1" , "Best Guess 2", "Best Guess
3"),xjust=0.5,yjust=0.5,
 lty=1,col=c(2,4,3))

Note that I had to change the name of the first vector to "x_vals" to 
get the plot to work.

Jim

Jim, 

Thank you very much for your feedback.   It is very much appreciated to know
this is possible.

I tried to reproduce your post, but I ran into a
problem:
> legend(emptyspace(rep(x_vals_1,3),c(y1_vals,y2_vals,y3_vals)), c("Best
Guess 1" , "Best Guess 2", "Best Guess 3"), xjust=0.5,
yjust=0.5, lty=1,col=c(2,4,3))
Error in legend(emptyspace(rep(x_vals_1, 3), c(y1_vals, y2_vals, y3_vals)),  : 
  could not find function "emptyspace"

I've searched via RSeek, but I have not been able to find anything on this
function.

Is emptyspace part of a package that I need to install? 

Thanks for any feedback. 


--- On Sun, 6/28/09, Jim Lemon <jim at bitwrit.com.au> wrote:
> From: Jim Lemon <jim at bitwrit.com.au>
> Subject: Re: [R] Automatically placing a legend in an area with the most
white space...
> To: "Jason Rupert" <jasonkrupert at yahoo.com>
> Cc: R-help at r-project.org
> Date: Sunday, June 28, 2009, 4:04 AM
> Jason Rupert wrote:
> > At one point I believe I heard of an R package that
> would automatically find the most empty space in a plot, and
> then that answer could then be used to intelligently place a
> legend.? 
> > I would like to try to apply that R package to the
> contrived example shown below, so thank you for any hints or
> tips that can be provided.???
> > x = seq(0, 1000, by = 1)
> > y1_vals<-rnorm(1000, mean = 0, sd = 50)
> > y2_vals<-rnorm(1000, mean = 25, sd = 40)
> > y3_vals<-rnorm(1000, mean = 115, sd = 40)
> > 
> > plot(x_vals, y1_vals, pch=22, col="dark red", bg >
"dark red", cex =0.3)
> > points(x_vals, y2_vals, pch=22, col="dark blue", bg >
"dark blue", cex =0.3)
> > points(x_vals, y3_vals, pch=22, col="dark green", bg >
"dark green", cex =0.3)
> > 
> > abline(h=0, col="dark red", lwd=1.5, lty=6)
> > abline(h=25, col="dark blue", lwd=1.5, lty=6)
> > abline(h=115, col="dark green", lwd=1.5, lty=6)
> > 
> > legend("topright", c("Best Guess 1" , "Best
Guess 2",
> "Best Guess 3"), bg="white", lwd = 2, title >
"Randomness:")
> > 
> >???
> Hi Jason,
> The good news is that the emptyspace function found the
> largest empty space in the plot. The bad news is that there
> was not nearly enough space to fit the legend:
> 
> legend(emptyspace(rep(x_vals,3),c(y1_vals,y2_vals,y3_vals)),
>  c("Best Guess 1" , "Best Guess 2", "Best Guess
> 3"),xjust=0.5,yjust=0.5,
> lty=1,col=c(2,4,3))
> 
> Note that I had to change the name of the first vector to
> "x_vals" to get the plot to work.
> 
> Jim
> 
>

That fixed it.  I thought I was getting the hang of R, but I guess I still have
a long way to go.

One last question regarding the dynamic placement of the legend in the location
on a plot with the largest empty space, is there a way to assure that the legend
doesn't go off the plot or is partially clipped by the boarder of the plot?

I posted the example to nabble:
http://n2.nabble.com/With-%22emptyspace%22-is-there-anyway-to-guarantee-legend-won%27t-be-off-the-plot--td3178773.html

Thanks for any feedback. 

Jason 




--- On Sun, 6/28/09, Stavros Macrakis <macrakis at alum.mit.edu> wrote:
> From: Stavros Macrakis <macrakis at alum.mit.edu>
> Subject: Re: [R] Automatically placing a legend in an area with the most
white  space...
> To: "Jason Rupert" <jasonkrupert at yahoo.com>
> Cc: "Jim Lemon" <jim at bitwrit.com.au>, R-help at
r-project.org
> Date: Sunday, June 28, 2009, 3:16 PM
> 
> install.packages('plotrix')
> 
> On Sun, Jun 28, 2009 at 3:51 PM,
> Jason Rupert <jasonkrupert at yahoo.com>
> wrote:
> 
> ...
> 
> Error in legend(emptyspace(rep(x_vals_1, 3), c(y1_vals,
> y2_vals, y3_vals)), ?:
> 
>  ?could not find function "emptyspace"
> 
> 
> 
> I've searched via RSeek, but I have not been able to
> find anything on this function.
> 
> 
> 
> Is emptyspace part of a package that I need to install?
> 
> 
> 
>