Align multiple ggplot2 plots with grid

Question

Context

I want to plot two ggplot2 on the same page with the same legend. http://code.google.com/p/gridextra/wiki/arrangeGrob discribes, how to do this. This alrea

Answer 1

1. Using cowplot package:

library(cowplot)
plot_grid(p1, p2, ncol=1, align="v")

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2. Using tracks from ggbio package:

Note: There seems to be a bug, x ticks do not align. (tested on 17/03/2016, ggbio_1.18.5)

library(ggbio)
tracks(data1=p1,data2=p2)