graph of my imagination in R - a map with spacing between bars and bar height

Question

I want to develop the following type of graph:

Where the postion determines the position of bar (not single direction rather both direction, although direction do not have special sense but aesthetic to look like a map) and height determines height of bar at each position. The following is corresponding dataset.

position <- c(0, 1, 3, 4, 5, 7, 8, 9,   0, 1, 2, 4.5, 7, 8, 9)
group <- c(1, 1, 1,  1, 1, 1, 1, 1,   2, 2, 2, 2, 2, 2, 2)
barheight <- c(0.5, 0.4, 0.4, 0.4, 0.6,  0.3, 0.4, 1, 0.75, 0.75,
           0.75, 1, 0.8, 0.2, 0.6)
mydf <- data.frame (position, group, barheight)
mydf
   position group barheight
1       0.0     1      0.50
2       1.0     1      0.40
3       3.0     1      0.40
4       4.0     1      0.40
5       5.0     1      0.60
6       7.0     1      0.30
7       8.0     1      0.40
8       9.0     1      1.00
9       0.0     2      0.75
10      1.0     2      0.75
11      2.0     2      0.75
12      4.5     2      1.00
13      7.0     2      0.80
14      8.0     2      0.20
15      9.0     2      0.60

Is their any graph package can do that. I would like welcome your innovative idea will be highly appreciated. I believe base R graphics or ggplot2 are flexible (but do not how to ) to do several type of graphs.

Answer 1

here is an example using ggplot2:

# top panel
ggplot(mydf, aes(position, factor(group), size = barheight)) + 
  geom_point() + opts(legend.position = "none")

# bottom panel
ggplot(mydf, aes(y = factor(group), 
                 xmin = position - 0.1, 
                 xmax = position + 0.1, 
                 ymin = group - barheight/2,
                 ymax = group + barheight/2)) + 
  geom_rect()

UPDATE

here is an example with the horizontal bar:

# arbitral bar length
bar <- data.frame(y = c(1, 1, 2, 2), x = c(0, 10, 1, 9))

ggplot() +
  geom_line(aes(x, factor(y), group = factor(y)), 
            bar, size = 2, colour = "skyblue") +
  geom_rect(aes(y = factor(group),
                xmin = position - 0.1, 
                xmax = position + 0.1, 
                ymin = group - barheight/2,
                ymax = group + barheight/2),
            mydf)

# bar length is from data range
ggplot(mydf) +
  geom_line(aes(position, factor(group), group = factor(group)),
            size = 2, colour = "skyblue") +
  geom_rect(aes(y = factor(group),
                xmin = position - 0.1, 
                xmax = position + 0.1, 
                ymin = group - barheight/2,
                ymax = group + barheight/2))

UPDATED AGAIN

I should have used geom_tile:

 ggplot(mydf, aes(position, factor(group), group = factor(group))) +
   geom_line(size = 2, colour = "skyblue") +
   geom_tile(aes(height = barheight))

UPDATED AGAIN

ggplot(mydf, aes(position, factor(group), group = factor(group))) +
   geom_line(size = 2, colour = "skyblue") +
   geom_tile(aes(height = barheight)) +
   geom_point(aes(x, y, group = NULL), data.frame(x = c(5, 5), y = c(1, 2)),
     size = 5, colour = "cyan")

Answer 2

Using very basic commands can give you more control over the layout and make things much more tidy in terms of graphical layout. In my approach I only use fields package to make horizontal lines, the rest is done with basic commands from graphics:

#Create example data with coordinates for plotting height of bars
position <- c(0, 1, 3, 4, 5, 7, 8, 9,   0, 1, 2, 4.5, 7, 8, 9)
group <- c(1, 1, 1,  1, 1, 1, 1, 1,   2, 2, 2, 2, 2, 2, 2)
barheight <- c(0.5, 0.4, 0.4, 0.4, 0.6,  0.3, 0.4, 1, 0.75, 0.75, 0.75, 1, 0.8, 0.2, 0.6)
y.start <- c(group-barheight/2)
y.end <- c(group+barheight/2)
mydf <- data.frame (position, group, barheight, y.start, y.end)
#Remove any crap from the plot
plot(0,type="n",ylim=c(0,3),xlim=c(0,10),axes=F,ylab="",xlab="")
#Create two horizontal lines
require(fields)
yline(1,lwd=4)
yline(2,lwd=4)
#Create text for the lines
text(10,1.1,"Group 1",cex=0.7)
text(10,2.1,"Group 2",cex=0.7)
#Draw vertical bars
segments(mydf$position[1:8],mydf$y.start[1:8],y1=mydf$y.end[1:8])
segments(mydf$position[9:15],mydf$y.start[9:15],y1=mydf$y.end[9:15])
#Add circle in custom position
require(plotrix)
draw.circle(mydf$position[14],2,0.2)
draw.circle(mydf$position[4],1,0.2)