Produce LaTeX from Rmarkdown

[awellis]

What is the easiest way to produce simple LaTeX from an RMarkdown file, i.e. without the preamble?

In other words, if I have this R code in a code chunk in an Rmd document:

plot(sin(seq(-pi, pi, length.out = 100)))

I would like to produce a .tex file containing an \includegraphics statement with the generated figure.

Is this possible, or would I be better off simply using Sweave?

[HanOostdijk]

Not quite sure what you want to achieve. If I knit the following Rmd file in the RStudio environment the result is a pdf file and a tex file with preamble. You can remove the preamble from the tex file.

---
# title: "Produce LaTeX from Rmarkdown"
# author: "awellis"
# date: "4/23/2020"
graphics: yes
output: 
  pdf_document: 
    keep_tex: true
---

## My plot

```{r sinus-plot, echo=FALSE}
plot(sin(seq(-pi, pi, length.out = 100)))
```

Regards Han

[awellis]

Thanks. What I want is a tex file without, a preamble, not a tex file from I have to remove the preamble. I can do that using Sweave.

I want to inlcude the generated tex file in maste tex file, from which I produce my manuscript.

best wishes
Andrew

[kjhealy]

In that case, just use knit and pandoc_convert directly from the console or a script. E.g.,

knitr::knit("test.Rmd") 

rmarkdown::pandoc_convert("test.md", to = "latex", output = "test.tex")

The knit command will produce test.md. The pandoc_convert command will produce test.tex, which by default will be a tex file without any preamble or \begin{document} ... \end{document} paraphernalia.

[awellis]

ah, thanks, that's what I was looking for. Seems about the same as using Sweave on an Rnw file.

[kjhealy]

In effect it is, yes. The main difference is that knitr's target output format is Markdown rather than .tex.

[Jason.C]

I’ve been curious about using LaTeX in RStudio and this has helped a lot. Thank you.
Out of curiosity, how would the plot command be written in the body of the Rnw file?

Cheers,
Jason the #rstatsnewbie

[awellis]

you can include figures like so:

\begin{figure}
    \center
<<fig, echo = FALSE, fig = TRUE>>=
plot(sin(seq(-pi, pi, length.out = 100)))
@
    \caption{This is a caption}
    \label{fig:sinplot}
\end{figure}

The code chunk is:

<< >>=
your code goes here
@

[Jason.C]

Thank you! I’ve use LaTeX for the last couple of years and am migrating to using R/RStudio for my analyses. This helps a lot with that process.

EDIT 1
What do these mean/do? Do they signal a change in environment or something?

@awellis

<< >>=
...

@

EDIT 2
Is there a good resource available, especially for citations, bibtex, references etc.?

Cheers,
Jason the #rstatsnewbie

[awellis]

That is noweb syntax. Code chunks are demarcated by the << >>= and documentation chunks begin with @. See here

The documentation chunks contain LaTeX code, so citations, etc. work as usual.

[HanOostdijk]

I have some examples of Rmd files that produce PDF files with none or more LaTeX.
See the github repository HanOostdijk/rmd_pdf_examples.

The bookdown package has a lot of functionality for 'citations, bibtex, references'. The names suggest that is useful only for books but it can also be used for articles. Chapter 2 of bookdown: Authoring Books and Technical Documents with R Markdown sections 6 and 8 describe how to use references and citations and the latexpdf part describes some specifics for the use of LaTeX.

[Jason.C]

This is great information. Thank you. I will definitely be looking into those references. Hopefully this will help me merge my workflow into one arena.

Thanks again.

Cheers,
~ Jason the #rstatsnewbie