[R] Trellis Plots: translating lattice xyplot() to ggplot()

[Rich Shepard]

   Hadley's ggplot2 book is quite old and a new version is in the works, but
not yet out. I've been using lattice graphics but the knitr package doesn't
support lattice, only basic plots and ggplot2. My Web searches for Trellis
plots in ggplot2 equivalent to those in lattice have not been productive.

   I would appreciate a pointer to a resource that would teach me how to
translate from lattice xyplot() to ggplot2 ggplot().

   This is one such plot needing translation:

xyplot(value ~ sampdate | variable, data=carlin.1.melt, rm.na = T)

Rich