I have an n*2 matrix (n is even), and regard each row as a point in the R^2 Euclidean Space. I can use the plot command in R to plot each row vector.
Then I generate another n/2*2 matrix, in which each row contains two integers between 1 and n, which index the rows for the two points in the matrix I just plotted.
However, if I want to draw a line between row vector in the n*2 matrix according to the rows in the newly established n/2*2 matrix, what command in R should I use? (For example, if the 1st row for the n/2*2 matrix is (1,3), I should draw a line coecting the 1st and 3rd row(point) in the n*2 matrix.)
Thanks!