march madness brackets with ggplot2 - r

Question

I'm trying to make a march madness bracket with ggplot2 and am having issues annotating the plot. Specifically, I've found that while I have no issues placing team names, I can't get the text to keep an absolute size. Hence, depending on the size of the window from which users view their ggplot object some team names look too big.
To demonstrate what I'm talking about, look at the following two images:
small bracket and medium bracket
In both images the size of the text is unchanged, despite the length of the bars being different. I'd like to know if there's a way to have the size of the text scale with the image, as opposed to being fixed in size. (My code is below; I apologize in advance for how tortuous it may seem.)
### Helper functions
first_evens <- function(x) {seq(from=2,to=2*x,length.out=x)}
first_odds <- function(x) {seq(from=1,to=2*x-1,length.out=x)}
### calculate y-values for horizontal lines:
### this is for top-left corner of the bracket,
### but multiplying sequences by -1 makes these
### values work for bottom right and left corners;
### final round has teams at y=2*off.set
r1.y.width <- 1.5*strheight(s="Virginia Common",units="in") # this effects the width of the first round
r1.y.offset <- 0.125*r1.y.width # this effects distance from y=0
r1.y <- seq(from=r1.y.offset,to=r1.y.offset+r1.y.width,length.out=16)
r2.y <- seq(from=mean(r1.y[1:2]),to=mean(r1.y[15:16]),length.out=8)
r3.y <- seq(from=mean(r2.y[1:2]),to=mean(r2.y[7:8]),length.out=4)
r4.y <- seq(from=mean(r3.y[1:2]),to=mean(r3.y[3:4]),length.out=2)
r5.y <- seq(from=mean(r4.y[1:2]),to=mean(r4.y[1:2]),length.out=1)
r6.y <- 1.5*r1.y.offset
### calculate horizontal bar start and stop coordinates
### note that there are 6 total rounds -- 5 rounds per quadrant
r1.x.width <- 1.25*strwidth("Viriginia Commonwealth","inches") # how long should horizontal lines be?
r1.x.offset <- 1
round.break.points <- -(seq(from=0,to=7*r1.x.width,by=r1.x.width)+r1.x.offset)
r1.x <- round.break.points[7:6]
r2.x <- round.break.points[6:5]
r3.x <- round.break.points[5:4]
r4.x <- round.break.points[4:3]
r5.x <- round.break.points[3:2]
r6.x <- round.break.points[2:1]
### calculate verticals line coordinates: these are based off of
### r1.y values. Round 5 verticals need to connect the four subtrees
### via the top-left <-> bottom-left and top-right <-> bottom-right
r1.verticals.start <- r1.y[first_odds(8)]
r1.verticals.stop <- r1.y[first_evens(8)]
r2.verticals.start <- r2.y[first_odds(4)]
r2.verticals.stop <- r2.y[first_evens(4)]
r3.verticals.start <- r3.y[first_odds(2)]
r3.verticals.stop <- r3.y[first_evens(2)]
r4.verticals.start <- r4.y[first_odds(1)]
r4.verticals.stop <- r4.y[first_evens(1)]
r5.verticals.start <- r5.y[1]
r5.verticals.stop <- -r5.y[1]
empty.bracket <- ggplot() + theme_bw() + theme(axis.line=element_blank(), axis.text.x=element_blank(), axis.text.y=element_blank(), axis.ticks=element_blank(), axis.title.x=element_blank(), axis.title.y=element_blank(), panel.border=element_blank(), panel.grid.major.x=element_blank(), panel.grid.minor.x=element_blank(), panel.grid.major.y=element_blank(), panel.grid.minor.y=element_blank(), plot.margin=unit(c(0,0,-6,-6),"mm"), text=element_text(size=12,hjust=0,vjust=0)) + coord_cartesian(ylim = c(-1.05*r1.y[16],1.05*r1.y[16]), xlim = c(1.025*r1.x[1],-1.025*r1.x[1]))
### add first round bars, and vertical connectors, make addition of each quadrant verbose
empty.bracket <- empty.bracket + geom_segment(aes(x=r1.x[1],y=r1.y,yend=r1.y,xend=r1.x[2])) + geom_segment(aes(x=r1.x[2],xend=r1.x[2],y=r1.verticals.start,yend=r1.verticals.stop)) + geom_segment(aes(x=r1.x[1],y=-r1.y,yend=-r1.y,xend=r1.x[2])) + geom_segment(aes(x=r1.x[2],xend=r1.x[2],y=-r1.verticals.start,yend=-r1.verticals.stop)) + geom_segment(aes(x=-r1.x[1],y=r1.y,yend=r1.y,xend=-r1.x[2])) + geom_segment(aes(x=-r1.x[2],xend=-r1.x[2],y=r1.verticals.start,yend=r1.verticals.stop)) + geom_segment(aes(x=-r1.x[1],y=-r1.y,yend=-r1.y,xend=-r1.x[2])) + geom_segment(aes(x=-r1.x[2],xend=-r1.x[2],y=-r1.verticals.start,yend=-r1.verticals.stop))
### add second round
empty.bracket <- empty.bracket + geom_segment(aes(x=r2.x[1],y=r2.y,yend=r2.y,xend=r2.x[2])) + geom_segment(aes(x=r2.x[2],xend=r2.x[2],y=r2.verticals.start,yend=r2.verticals.stop)) + geom_segment(aes(x=r2.x[1],y=-r2.y,yend=-r2.y,xend=r2.x[2])) + geom_segment(aes(x=r2.x[2],xend=r2.x[2],y=-r2.verticals.start,yend=-r2.verticals.stop)) + geom_segment(aes(x=-r2.x[1],y=r2.y,yend=r2.y,xend=-r2.x[2])) + geom_segment(aes(x=-r2.x[2],xend=-r2.x[2],y=r2.verticals.start,yend=r2.verticals.stop)) + geom_segment(aes(x=-r2.x[1],y=-r2.y,yend=-r2.y,xend=-r2.x[2])) + geom_segment(aes(x=-r2.x[2],xend=-r2.x[2],y=-r2.verticals.start,yend=-r2.verticals.stop))
### add third round
empty.bracket <- empty.bracket + geom_segment(aes(x=r3.x[1],y=r3.y,yend=r3.y,xend=r3.x[2])) + geom_segment(aes(x=r3.x[2],xend=r3.x[2],y=r3.verticals.start,yend=r3.verticals.stop)) + geom_segment(aes(x=r3.x[1],y=-r3.y,yend=-r3.y,xend=r3.x[2])) + geom_segment(aes(x=r3.x[2],xend=r3.x[2],y=-r3.verticals.start,yend=-r3.verticals.stop)) + geom_segment(aes(x=-r3.x[1],y=r3.y,yend=r3.y,xend=-r3.x[2])) + geom_segment(aes(x=-r3.x[2],xend=-r3.x[2],y=r3.verticals.start,yend=r3.verticals.stop)) + geom_segment(aes(x=-r3.x[1],y=-r3.y,yend=-r3.y,xend=-r3.x[2])) + geom_segment(aes(x=-r3.x[2],xend=-r3.x[2],y=-r3.verticals.start,yend=-r3.verticals.stop))
### add fourth round
empty.bracket <- empty.bracket + geom_segment(aes(x=r4.x[1],y=r4.y,yend=r4.y,xend=r4.x[2])) + geom_segment(aes(x=r4.x[2],xend=r4.x[2],y=r4.verticals.start,yend=r4.verticals.stop)) + geom_segment(aes(x=r4.x[1],y=-r4.y,yend=-r4.y,xend=r4.x[2])) + geom_segment(aes(x=r4.x[2],xend=r4.x[2],y=-r4.verticals.start,yend=-r4.verticals.stop)) + geom_segment(aes(x=-r4.x[1],y=r4.y,yend=r4.y,xend=-r4.x[2])) + geom_segment(aes(x=-r4.x[2],xend=-r4.x[2],y=r4.verticals.start,yend=r4.verticals.stop)) + geom_segment(aes(x=-r4.x[1],y=-r4.y,yend=-r4.y,xend=-r4.x[2])) + geom_segment(aes(x=-r4.x[2],xend=-r4.x[2],y=-r4.verticals.start,yend=-r4.verticals.stop))
### add fifth round: add necessary horizontal bars and then
### vertical bars
empty.bracket <- empty.bracket + geom_segment(aes(x=r5.x[1],y=r5.y,yend=r5.y,xend=r5.x[2])) + geom_segment(aes(x=r5.x[1],y=-r5.y,yend=-r5.y,xend=r5.x[2])) + geom_segment(aes(x=r5.x[2],y=-r5.y, yend=r5.y, xend=r5.x[2])) + geom_segment(aes(x=-r5.x[1],y=r5.y,yend=r5.y,xend=-r5.x[2])) + geom_segment(aes(x=-r5.x[1],y=-r5.y,yend=-r5.y,xend=-r5.x[2])) + geom_segment(aes(x=-r5.x[2],y=-r5.y,yend=r5.y,xend=-r5.x[2]))
### due to symmetry, the 6th (and final round)
empty.bracket <- empty.bracket + geom_segment(aes(x=r6.x[1],y=r6.y,xend=r6.x[2],yend=r6.y)) + geom_segment(aes(x=-r6.x[1],y=-r6.y,xend=-r6.x[2],yend=-r6.y))
### add winner location
empty.bracket <- empty.bracket + geom_segment(aes(x=mean(r6.x),xend=-mean(r6.x),y=0,yend=0))
### put some test labels on the bracket slots
Labels <- c("Alabama", "Alaska", "Arizona", "Arkansas", "Virginia Commonwealth")
TextFrame <- data.frame(X = r1.x[1], Y = sample(r1.y,5), LAB = Labels)
TextFrame <- transform(TextFrame, w = strwidth(LAB, 'inches') + 0.05, h = strheight(LAB, 'inches') + 0.5)
### display results
empty.bracket + geom_rect(data = TextFrame, aes(xmin = X, xmax = X + w, ymin = Y, ymax = Y + h),alpha=0) + geom_text(data=TextFrame,aes(x=X,y=Y,label=LAB),size=rel(3),hjust=0,vjust=0)

Answer 1

I'll take your question in a few separate parts.
Window size:
Hence, depending on the size of the window from
which users view their ggplot object some team names
look too big.
When viewing an R graphic, the text size remains constant, whilst the graphic objects scale to the window. This means that what you see in an R graph window, isn't necessary the same as what you'll get when you print it out (unless you use the savePlot command).
Text scaling:
In both images the size of the text is unchanged, despite the
length of the bars being different. I'd like to know if there's a
way to have the size of the text scale with the image, as opposed to
being fixed in size.
I believe the short answer is no. You specify the text size and it's fixed. However, if outputting to a pdf device, you could scale the text size according to the width of the pdf.