knitr does not inject the R output into a pandoc/markdown documemt - r

I'm trying to use knitr to inject R code and its output in pandoc/markdown documents. But I do not get knitr to inject the R output. I have tried decorating the R chunks with r and with{r}. Both doesn't work. Here my sample setup (with ```r):
First I show the command I issue, then I list the two files subsequently used by this command.
Here the command for the shell:
$ r CMD BATCH knitme.R
Content of knitme.R:
library("knitr")
pandoc("foo.md")
Content of foo.md:
# My knitr test
```r
1+1
```
Did this print *the result* as well?
Here a graph:
```r
plot(1:10)
```
And where is the graph?
After I ran the command I do get, as expected a new file foo.html. Here its content:
<h1 id="my-knitr-test">My knitr test</h1>
<pre class="sourceCode r"><code class="sourceCode r"><span class="dv">1+1</span></code></pre>
<p>Did this print <em>the result</em> as well?</p>
<p>Here a graph:</p>
<pre class="sourceCode r"><code class="sourceCode r">
<span class="kw">plot</span>(<span class="dv">1</span>:<span class="dv">10</span>)</code></pre>
<p>And where is the graph?</p>
This result shows that pandoc converted the input file foo.md, *but knitr did not inject the Output of the execeutes R code.
What do I miss? any help appreciated!

You should first call knit() on an R Markdown (*.Rmd) document, which produces a Markdown (*.md) document, and that is when you can run pandoc().
library(knitr)
knit('foo.Rmd')
pandoc('foo.md')
The R scripts in examples 084 and 088 as mentioned on the flaky website have illustrated how. Please also take a look at the Rmd documents to learn the syntax for R code chunks in R Markdown. If you still have 5 minutes, watch the video on the homepage, and I think all the confusion should be gone.

Related

Compile Bookdown to Markdown?

Is there any way to take a Bookdown project, and build it as Markdown instead of HTML or TeX?
I ask because I need to post-process the final Markdown output from Bookdown, in order to extract R and Python notebooks for download.
In more detail, I am using Bookdown to build a textbook that embeds notebooks to download, where the notebooks contain subsets of the code and text in the bookdown .Rmd files. For example, a single chapter could contain more than one notebook.
In order to do this, I put start and end comment markers in the RMarkdown input text to identify the section that will be a notebook, and then post-process the generated Markdown files to extract the notebook section. As in something like:
<!--- notebook: first_section.Rmd
-->
Some explanation, maybe using Bookdown extra markup such as #a_citation.
```{r}
a <- 1
a
```
<!--- end of notebook
-->
More markdown.
```{r}
# More code not in notebook.
b <- 2
```
Obviously I could use the input RMarkdown pages, but this would be ugly, because all the extended Bookdown markup such as citations, cross-references and so on, would appear in raw and ugly form in the generated notebook. So I'd really like to be able to get the final output Markdown, after merging, resolving of citations and cross references. Is there any way of doing that?
My question is similar to this as-yet unanswered question, but adds my motivation for an official solution to this problem.
With the latest version of bookdown on CRAN, you can use the output format bookdown::markdown_document2, e.g.,
output:
bookdown::markdown_document2:
base_format: rmarkdown::md_document
variant: gfm

How can I convert a Rmd document to a jupyter notebook

I would like to convert a rmarkdown .Rmd document to a jupyter notebook .ipynb.
I found that converting from jupyter to rmd is easy using as described in reference page but for some reason (...) the Rstudio team did not do the other way.
For instance I would like to convert
---
title: "Untitled"
author: "statquant"
date: "03/09/2019"
output: html_document
---
```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```
## R Markdown
This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see <http://rmarkdown.rstudio.com>.
When you click the **Knit** button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this:
```{r cars}
summary(cars)
```
## Including Plots
You can also embed plots, for example:
```{r pressure, echo=FALSE}
plot(pressure)
```
Note that the `echo = FALSE` parameter was added to the code chunk to prevent printing of the R code that generated the plot.
After checking, the silver bullet seems to be jupytext
It allows you to convert from or to markdown, rmarkdown, python, ipynb, etc.
This can actually allow you a pretty neat workflow
write a simple R script, script.R, that you can spin into a Rmd document
use knitr::spin('script.R', knit = FALSE) to transform it to Rmd
use jupytext --to notebook script.Rmd to create script.ipynb
share or execute the notebook
sos-rmarkdown provides yet another Rmarkdown to Jupyter notebook converter. The unique features include its support for inline expressions using markdown-kernel, use of multiple kernels in one notebook (using a SoS kernel) to accommodate code blocks in multiple languages, and the ability to execute generated notebook using sos-papermill. It also uses cell meta data to control the display of input and output of code blocks in Jupyter Lab and exported HTML reports.
To use this tool, you can install sos-rmarkdown from pip or conda-forge, then run the converter with command
sos convert input.Rmd output.ipynb
or use option --execute to execute the converted notebook
sos convert input.Rmd output.ipynb --execute
Disclaimer: I am the author of sos-rmarkdown.
Here is another way.
The detailed answer (to convert .rmd to .ipynb) is described here: https://gist.github.com/ramnathv/10012123
TL;DR
Use a 3rd-party Python package notedown with sed command as follows:
1) Install a 3rd-party python package which does the conversion for us
$ pip install notedown
2) Use the installed package to convert from your *.Rmd file (or *.md) to *.ipynb and run the terminal command:
$ notedown example.Rmd | sed '/%%r/d' > example.ipynb

Code / Process for running rmarkdown in base R

All my codes developed in base R and I don't want to use RStudio, however I want to use rmarkdown feature in base R which is available in Rstudio.
I have downloaded rmarkdown package in base r, but not able to derive a code to publish my work
All the output of my codes written in R should be view able through web browser.
First make sure you're using .Rmd as your file extension. If not, rename it to a .Rmd extension. Make sure you have Pandoc installed on your OS.
Next, add the following to the top of the file:
---
title: "Your notebook title"
output: html_document
---
output: could take any value. You can pass in the value of ioslides_presentation for example if you want but it looks like html_document fits the criteria of what you want pretty well.
Once you have that, write your code in any editor (or the R console if you prefer). Use the code chunks and markdown text formatting as you normally would:
```{r}
plot(1:10)
```
In my base R Console, this is how mynotebook.Rmd looks like:
Finally, use the render() function from rmarkdown. You can either attach it and run render():
library(rmarkdown)
render("mynotebook.Rmd")
Or, run rmarkdown::render("mynotebook.Rmd").
Notice that the use of RStudio is not required at all since Pandoc is the document converter performing this task. For the so inclined, this is what its documentation has to say:
When you run render, R Markdown feeds the .Rmd file to knitr,
which executes all of the code chunks and creates a new markdown (.md)
document which includes the code and it's output.
The markdown file generated by knitr is then processed by pandoc
which is responsible for creating the finished format.
This may sound complicated, but R Markdown makes it extremely simple
by encapsulating all of the above processing into a single render
function.

Sweave to R markdown file conversion - code or converters available?

I am not sure if this type of question complies with the SO rules for well-defined questions ;) ... anyway:
I want to convert several R Sweave files (.Rnw) to R markdown files (.Rmd). Jeromy Anglin has posted on this matter here but there is no code supplied. I tried to use pandoc, but of course pandoc cannot handle the chunk tags and inline code tags correctly.
Consclusion: I guess I will have do write some code to parse my .Rnw files to prepare them for pandoc conversion. Thus my questions:
Is there a better way to go?
Does someone by chance have code
available that will do the job?
TIA
As #Karl commented, LaTeX --> markdown is not a trivial conversion as there are far more options and environments available in LaTeX compared to markdown. You are probably best off working with something like pandoc (see Demo #5). Basically, instead of doing
.Rnw --> .Rmd --> .md
you would do
.Rnw --> .tex --> .md
with pandoc. If you really want to go from .Rnw --> .Rmd, you may want to check out the pander package to write a function to extract code chunks, convert the remaining LaTeX content to markdown, and then re-insert the code chunks into the markdown document.

Can I use a knitr inline expression in the title of a latex document?

I'd like to use a Knitr/Sweave in-line call (\Sexpr{}) in the title of a LaTeX document, after the \begin{document} command but before the \maketitle command. The in-line R code would extract one or two pieces of information from an R data-frame created early in the R script I'm embedding in LaTeX.
I have a couple of Knitr chunks that create a data.frame from which I derive the information I want to put in the Title. I've tried placing these chunks between LaTeX's \begin{document} call and the \title code, like this:
\documentclass
[LaTex Preamble]
\begin{document}
[%% Knitr chunks that initialize an R data-frame]
\title \Sexpr{--a snippet of R code that extracts an element from the data-frame --}
\maketitle
... (rest of the LaTeX document)
and I've also tried putting the Knitr chunks in the preamble to the LaTeX code before \begin{document} statement.
But in Knitr seems to ignore code (other than initialization) that is placed ahead of the \maketitle call in LaTeX, so the in-line snippets included the title look like errors to Latex and it halts output.
I can't find any information in the Knitr documentation on including in-line code in the Title of a LaTeX document.
Any ideas?
OK: Found the solution thanks to the hint from #ben-bolker below. Ben uses the formatting of R chunks before output to an RNW file (in a 2-step Knitr process: latex -> rnw -> pdf) . But I'm compiling the LaTeX file to PDF in one-step without going to an RNW file from inside TeXShop (on Mac OSX). I found that I could get Ben's example to work using the RNW delimiters (<<>>=) and one-step compiling. But I couldn't mix the usual LaTeX chunk-delimiters (%%begin.rcode and %% end.rcode) and the RNW in-line statement hook (\Sexpr{}). The latter didn't work no matter how I fiddled with it. Eventually I found that the correct in-line hook for LaTeX is \\rinline{}.
It's not very clear in the Knitr documentation that this is the required format for LaTeX and I found it eventually mainly thanks to Ben's example. Best, Peter
Update 2 ... and then there's RTFM (or the 'cheat sheet' in this case): http://cran.r-project.org/web/packages/knitr/vignettes/knitr-refcard.pdf
Hmm. The following file works for me:
\documentclass{article}
<<echo=FALSE>>=
x <- 5
#
\title{The number is \Sexpr{x^2}}
\begin{document}
\maketitle
Some stuff
\end{document}
with knitr version 0.8 on Ubuntu 10.04, via knit2pdf("knitr_title.Rnw") ...

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