I am a new user to knitr. I know that knitr can "tangle out" (taken from the Literate programming community) or extract source code blocks into an R script file. Being an org-mode-user, I am used to being able to specify a specific file for each code block, with potentially the same file for different blocks. When "tangling" or extracting source in org-mode, instead of having one output code file, several code files are produced (this helps with modularity in large projects).
I wonder if something similar is possible in knitr? Can I specify the output file in knitr on a block by block basis?
There are at least two different readings of your question, each requiring slightly different workflows.
If each chunk is going to be written into a separate output document, then to assist modularity, you should split the reporting part down into multiple documents. Since knitr supports child documents, you can always recombine these into larger documents in any combinations that you like.
If you want conditional execution of some chunks, and there are a few different combinations of conditions that can be run, use an R Markdown YAML header, and include a params element.
----
params:
report_type: "weekly" # should be "weekly" or "yearly"
----
You can set which chunks are run by setting the eval and include chunk options.
```{r, some_chunk, eval = params$report_type == "weekly", include = params$report_type == "weekly"}
# chunk contents
```
Related
I have read previously asked similar questions here, here, and here (among many more).
Unfortunately, none of the solutions offered to those questions seem to solve my issue.
I tried the function written by #bryanshalloway here but that did not have the desired result.
For more context, I am producing scientific manuscripts using an R Markdown workflow. I perform EDA in one notebook and later come back to write the manuscript in a different notebook. I import the data, wrangle it, create tables, and do some basic visualizations in the EDA notebook and include narrative text (mostly for myself).
I then create a separate notebook to write the manuscript. To keep it reproducible, I want to include all of the steps from the EDA with respect to data import, tidying, and wrangling, however I do not need the commentary that went along with it. Additionally, I may want some (but definitely not all) of the tables and basic visualizations I created during the EDA, but I would need to build them up substantially to get them publication ready.
My current workflow is just copying and pasting the relevant code chunks and then adding to those where necessary for tables and figures (i.e., adding labels and captions to a ggplot).
Is there a way to "source" these individual code chunks from one R Markdown file/R Notebook into another? Perhaps using knit_child (but not bring the entire R Markdown file into the current parent file)?
I would like to avoid copying the desired code chunks into separate R scripts.
Thanks!
It is very possible with knitr purl and spin:
Ok lets say this is your initial Rmarkdown report:
call the file report1.Rmd
---
title: Use `purl()` to extract R code
---
The function `knitr::purl()` extracts R code chunks from
a **knitr** document and save the code to an R script.
Below is a simple chunk:
```{r, simple, echo=TRUE}
1 + 1
```
Inline R expressions like `r 2 * pi` are ignored by default.
If you do not want certain code chunks to be extracted,
you can set the chunk option `purl = FALSE`, e.g.,
```{r, ignored, purl=FALSE}
x = rnorm(1000)
```
Then you go to the console and purl the file:
> knitr::purl("report1.Rmd")
this creates an R file called report1.R in the same directory you are in,
with only the chunks that are not purl=false.
Its an simple R script looking like this:
## ---- simple, echo=TRUE----------------------------------------------------------------------------
1 + 1
Lets rename the file for safety purposes:
> file.rename("report1.R", "report_new.R")
Finally lets spin it back to report_new.Rmd :
> knitr::spin("report_new.R", format = "Rmd", knit=F)
This gives you a new Rmd file called report_new.Rmd containing only the relevant chunks and nothing else
```{r simple, echo=TRUE}
1 + 1
```
I generate reports using rmarkdown::render() function on a list of .Rmd files and I get one HTML file for each of them.
That was fine until my dataset got bigger and my reports now contain >100 figures... The HTML files often end-up being >100MB and I now have some very big ones (~500MB).
The .Rmd is separated in several chunks so one might think I have to split my .Rmd in smaller files (let's say one chunk per file).
This is not (easily) doable because the .Rmd defines a data-processing workflow (figures generated in chunk3 require processings made in chunk1 and chunk2).
I would like to know if it is possible to split the rendering in several HTML files automatically.
Ideally I dream about a 'splitHeader' argument in render() that would generate separate HTML file for each header of a specified level.
I guess an ugly solution is to manually add conditional statements for every chunk/header that I would like rendered (or not), and call render() several time with different arguments. But this is extremely inefficient (and ugly, I said that already)...
Would somebody have suggestions to achieve that ?
I am not sure if this solve (or at least help to solve): You can have multiple independent .Rmd files (childs) dividing the content as you like. In a "Mother" file, you can add the child using:
```{r child = "yourChild.Rmd"}
```
The child .Rmd files should no contain any header information. That is, delete the first lines in you .Rmd that are something like:
---
title: "Your Title"
author: "Your name"
output: html_notebook
---
I'm using Rmarkdown/Bookdown to write a paper/PDF document, which is an amazing tool #Yihui, thanks! Now I'm trying to include a table I have already put in LaTeX into the document by reading in this external .tex file. However, when knitting in RStudio with a \include{some-file.tex} or input{some-file.tex} in the body of the .Rmd outside of a chunk a LaTeX Error: Can be used only in preamble. is produced and the process stopped. I haven't found a way how to directly input through knit or otherwise into a chunk as well.
I found this question here: Rmarkdown v2, embed Latex document, although while the question is similar, there is no answer which would reflect how to input/include .tex-files into an .Rmd.
Why would I want this? Sometimes LaTeX tables offer more layout options than building directly in R, like for tables only with text rather than R-computed numbers. Also, when running models on a cluster, exporting results directly into .tex ready for compilation saves a lot of computation compared to have to open all these heavy .RData files just for getting the results into a PDF. Similarly, having sometimes multiple types of reports with different audiences, having the full R code in one main .Rmd file and integrating only the necessary results in other files reduces complexity by not having to redo all steps in each file newly. This way, I can keep one report with the full picture and do not have to check if I included every little change in various documents simultaneously.
So finally the question is how to get prepared .tex-Files into a .Rmd-document?
Thanks for your answers!
I am working on a LaTeX report template that automatically generates a beamer document, pulling in figures from specified directories and placing them one per slide.
Here is an example of the code that I am using for this, as a code chunk in my .Rnw document:
<<results='asis',echo=FALSE>>=
suppressPackageStartupMessages(library("Hmisc"))
# get the plots from the common directory
Barplots_dir<-"/home/figure/barplots"
Barplots_files<-dir(Barplots_dir)
# create a beamer slide for each plot
# use R to output LaTeX markup into the document
for(i in 1:length(Barplots_files)){
GroupingName<-gsub("_alignment_barplot.pdf", "", Barplots_files[i]) # strip this from the filename
file <- paste0(Barplots_dir,"/",Barplots_files[i]) # path to the figure
cat("\\subsubsection{", latexTranslate(GroupingName), "}\n", sep="") # don't forget you need double '\\' because one gets eaten by R !!
cat("\\begin{frame}{", latexTranslate(GroupingName), " Alignment Stats}\n", sep="")
cat("\\includegraphics[width=0.9\\linewidth,height=0.9\\textheight,keepaspectratio]{", file, "}\n", sep="")
cat("\\end{frame}\n\n")
}
#
However I recently came across this article by Yihui Xie which includes a remark about cat("\\includegraphics{}") being a bad idea. Is there a reason for this, and is there a better option?
To be clear, these figures are generated by other programs as part of a larger pipeline; generating them within the document is not an option, but I need the document to be able to dynamically find and insert them into the report. I know that there are some capabilities to do this directly from within LaTeX itself but cat'ing out the LaTeX markup I need seemed like an easier and more flexible task.
cat("\\includegraphics{}") is likely to be a bad idea if you are from the old Sweave world (where one might need to open a graphics device, draw a plot, close the device, and cat("\\includegraphics{}")). No kittens will be killed as long as you understand what you are doing. Your use case seems to be very reasonable to me, and I don't have a better approach.
I want to write an R function which processes some data and then automatically outputs an html report. This report should contain some fixed text, some text changing according to the underlying data and some figures.
What is the best way to go?
R2HTML or knitr?
What are the advantages of one over the other?
As far as I understood R2HTML allows me to build the html file sequentially while knitr already operates on an predefined .Rhtml file.
So, either use R2HTML or stitch and spin from knitr for on the fly report generation.
I would appreciate any suggestions or hints.
I grab this nice opportunity to promote pander a bit :)
This package was written for similar reasons like #Yihui's great knitr, although I wanted to let users really concentrate on the text and R code without dealing with chunk options etc. So letting users generate pretty HTML, pdf or even docx or odt output automatically with some predefined options.
These options affects e.g. the cache engine (handling dependencies without any chunk options) or the default plot options (let it be a "base" R graphics, lattice or ggplot2), so that you do no thave to set the color palette or the minor grid in each of your plots, just once - or live with the package defaults :)
The package captures the results (besides errors/warnings and other messages and the output) of all run R expression and can convert to Pandoc's markdown automatically. There are some helper functions that let you convert the resulting document written in a brew-like syntax automatically to e.g. HTML if you have pandoc installed, or export R objects to markdown/HTML/any other supported format in a live R session with a reference class.
Short demo:
brew file
Pandoc.brew('file_name.brew', output = 'foo.html', convert = 'html')
HTML output
knitr, every time. Handles graphics, lets you write your report with markdown instead of having to write html everywhere (if you want), caches things, makes coffee for you etc.
You can also build an HTML file sequentially as long as you have a decent text editor like Emacs/ESS or RStudio, etc. R2HTML is excellent in terms of its wide support to many R objects (see methods(HTML)), but I'll probably frown on RweaveHTML() due to its root Sweave().
That said, I think it may be a good idea to combine R2HTML and knitr, e.g.
# A LOESS Example
```{r loess-demo, results='asis'}
cars.lo <- loess(dist ~ speed, cars)
library(R2HTML)
HTML(cars.lo, file = '')
```
I was using the R Markdown syntax in the above example. The key is results='asis' which means to writing raw HTML code into the output.
I believe that you can also use Sweave to create HTML files, though I have heard that knitr is easier to use.