В базе R ...
plot(pos, type = 'n', xlim = range(c(start, end)), ylim = c(13,0))
grid()
segments(start, pos, end, pos)
Чтобы получить более точно, как ваша фигура ...
r <- par('usr')
plot(pos, type = 'n', xlim = range(c(start, end)), ylim = c(13.5,0.5), xlab = '',
xaxt = 'n', yaxt = 'n', panel.first = rect(r[1], r[3], r[2], r[4], col = 'goldenrod'))
# abline(h = 1:13, col = 'white')
# abline(v = 1:13, col = 'white')
grid(lty = 1, col = 'white')
axis(1, 1:13, 1:13, cex.axis = 0.8)
axis(2, 1:13, 1:13, las = 1, cex.axis = 0.8)
segments(start, pos + 0.5, end, pos + 0.5, lwd = 2)