033-file-extension.Rnw

\documentclass{article}

\begin{document}

We want the file extension when including a figure into LaTeX.

<<setup>>=
knit_hooks$set(plot = function(x, options) {
  x = paste(x, collapse = '.') # x is file.ext now instead of c(file, ext)
  paste0('\\end{kframe}', hook_plot_tex(x, options), '\\begin{kframe}')
})
@

You should see \textbackslash{}includegraphics\{test.pdf\} instead of \textbackslash{}includegraphics\{test\}.

<<test-a>>=
# pdf figure
plot(1)
@

<<test-b, dev='png'>>=
# png figure
plot(2)
@

\end{document}