ggplot2 line plot order

Question

I have a series of ordered points as shown below:

However when I try to connect the points by a line, I get the following output:

The plot is connecting 26 to 1 and 25 to 9 and 10 (some of the errors), instead of following the order. The code for plotting the points is given below:

p<-ggplot(aes(x = x, y = y), data = spat_loc)
p<-p + labs(x = "x Coords (Km)", y="Y coords (Km)") +ggtitle("Locations")
p<-p + geom_point(aes(color="Red",size=2)) + geom_text(aes(label = X))
p + theme_bw()

Plotting code:

p + 
geom_line((aes(x=x, y=y)),colour="blue") +
theme_bw()

The file which contains the locations have the following structure:

X    x    y
1    210  200 
.
.
.

where X is the numeric ID and x and y are the pair of co-ordinates.

What do I need to do to make the line follow the ordering of points?

Answer 1

geom_path() will join points in the original order, so you can order your data in the way you want it joined, and then just do + geom_path(). Here's some dummy data:

dat <- data.frame(x = sample(1:10), y = sample(1:10), order = sample(1:10))
ggplot(dat[order(dat$order),], aes(x, y)) + geom_point() + geom_text(aes(y = y + 0.25,label = order)) +
  geom_path()