TikZDevice: Add \caption{} and \label{} to TikZ diagram using R - r

Question

I've created a for loop that outputs several plots (via ggplot2) from R into a single .tex file using the tikzDevice package. This makes it easier to include multiple diagrams from within a latex document using a single command that points to the .tex file outputted from R (say 'diagrams.tex'): \include{diagrams}.
However, I would also like to wrap each tikzpicture with the \begin{figure} environment, so that I can insert two additional lines into each respective figure: \caption{} and \label{}.
Question: is there a way to include the figure wrapper, caption, and label latex commands directly, for each respective ggplot image (from my R loop), in the outputted .tex file?
Here is reproducible R code that generates a file 'diagrams.tex' containing 3 ggplots:
require(ggplot2)
require(tikzDevice)
## Load example data frame
A1 = as.data.frame(rbind(c(4.0,1.5,6.1),
c(4.0,5.2,3.5),
c(4.0,3.4,4.3),
c(4.0,8.2,7.3),
c(4.0,2.9,6.3),
c(6.0,3.9,6.6),
c(6.0,1.5,6.1),
c(6.0,2.7,5.3),
c(6.0,2.9,7.4),
c(6.0,3.7,6.0),
c(8.0,3.9,4.2),
c(8.0,4.1,3.5),
c(8.0,3.7,5.8),
c(8.0,2.5,7.5),
c(8.0,4.1,3.5)))
names(A1) = c("state","rmaxpay","urate")
i = 2
## name output file
tikz( 'diagrams.tex' )
for (i in 2:4){ #begin LOOP
st = i*2
df = NULL
df = subset(A1, state == st , select = c(2:3))
print( # start print
ggplot(df, aes(rmaxpay,urate)) + geom_point()
) # end print
} #end LOOP
dev.off()

Answer 1

There may be a way to do this with plot hooks but as it is you can do it by using the console option and sink():
require(ggplot2)
require(tikzDevice)
## Load example data frame
A1 = as.data.frame(rbind(c(4.0,1.5,6.1),
c(4.0,5.2,3.5),
c(4.0,3.4,4.3),
c(4.0,8.2,7.3),
c(4.0,2.9,6.3),
c(6.0,3.9,6.6),
c(6.0,1.5,6.1),
c(6.0,2.7,5.3),
c(6.0,2.9,7.4),
c(6.0,3.7,6.0),
c(8.0,3.9,4.2),
c(8.0,4.1,3.5),
c(8.0,3.7,5.8),
c(8.0,2.5,7.5),
c(8.0,4.1,3.5)))
names(A1) = c("state","rmaxpay","urate")
i = 2
fn <- "diagrams.tex"
if(file.exists(fn)) file.remove(fn)
for (i in 2:4){ #begin LOOP
st = i*2
df = NULL
df = subset(A1, state == st , select = c(2:3))
cat("\\begin{figure}\n", file = fn, append=TRUE)
sink(fn, append=TRUE)
tikz(console = TRUE)
print( # start print
ggplot(df, aes(rmaxpay,urate)) + geom_point()
) # end print
dev.off()
sink()
cat(paste("\\caption{figure}\\label{fig:",i,"}\n",sep=""), file = fn, append=TRUE)
cat("\\end{figure}\n", file = fn, append=TRUE)
} #end LOOP