[R] Lattice, combine histogram and line graph

[Gabor Grothendieck]

On Sun, Jan 9, 2011 at 8:13 PM, Jim Burke <j.burke at earthlink.net> wrote:
> Hello everyone,
>
> I have a simple histogram of gasoline prices going back a few years that I
> want to insert a line graph of consumer price index (cpi) over the
> histogram.  I have looked through the "Lattice" book by Deepayan Sarkar but
> don't see anything there. How might this be done? An example would be
> wonderful.
>
> Current code snippet follows. For example additional field to add as a line
> graph would be a cpi calculation like "gas_data$regular * (2010_cpi /
> gas_data$year )".
>
> xyplot( regular ~ as.Date(gas_data$dates,"%b %d, %Y") , data = gas_data,
>       type = c("g", "h" ))

xyplot.zoo in the zoo package has facilities for drawing multiple time
series using lattice graphics or in different panels.  The
documentation has many examples.

library(zoo)
library(lattice)

z1 <- zoo(1:6)
z2 <- z1^2
z <- cbind(z1, z2)
xyplot(z) # different panels
xyplot(z, screen = 1) # all on one panel

?xyplot.zoo
example(xyplot.zoo)
vignette(package = "zoo") # lists available vignettes

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