Producing documents / documentation directly in R means that you closely interweave (knit) your analysis and R code together. This reduces rework time when you want to change or extend your code, it reduces time to produce new versions, and because it's code it's easier to apply strong software development principles to it.
Oh, and you don't need to spend hours making text boxes in powerpoint! Win ;-)
There are two languages which you can knit your r code into:
Markdown is great for very quick generation and light (or css driven) styling and is what this section focusses on. LaTeX is excellent for producing stunning, more flexible documents.
The following text is the default text that gets created when you produce a new rmarkdown file in rstudio
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:
summary(cars)
## speed dist
## Min. : 4.0 Min. : 2.00
## 1st Qu.:12.0 1st Qu.: 26.00
## Median :15.0 Median : 36.00
## Mean :15.4 Mean : 42.98
## 3rd Qu.:19.0 3rd Qu.: 56.00
## Max. :25.0 Max. :120.00
You can also embed plots, for example:
Note that the echo = FALSE parameter was added to the code chunk to prevent printing of the R code that generated the plot.
The following text is part of the standard documentation on rmarkdown. I pull it from github.com/rstudio/rmarkdown and integrate it using knitr. It is better than I could produce and the act of integrating it gives an extra example of useful ways to build documents.
This document provides quick references to the most commonly used R Markdown syntax. See the following articles for more in-depth treatment of all the capabilities of R Markdown:
*italic* **bold**
_italic_ __bold__
# Header 1
## Header 2
### Header 3
Unordered List:
* Item 1
* Item 2
+ Item 2a
+ Item 2b
Ordered List:
1. Item 1
2. Item 2
3. Item 3
+ Item 3a
+ Item 3b
R code will be evaluated and printed
```{r}
summary(cars$dist)
summary(cars$speed)
```
There were 50 cars studied
Use a plain http address or add a link to a phrase:
http://example.com
[linked phrase](http://example.com)
Images on the web or local files in the same directory:
A friend once said:
> It's always better to give
> than to receive.
Plain code blocks are displayed in a fixed-width font but not evaulated
```
This text is displayed verbatim / preformatted
```
We defined the `add` function to
compute the sum of two numbers.
LaTeX Equations
Inline equation:
$equation$
Display equation:
$$ equation $$
Three or more asterisks or dashes:
******
------
First Header | Second Header
------------- | -------------
Content Cell | Content Cell
Content Cell | Content Cell
Reference Style Links and Images
A [linked phrase][id].
At the bottom of the document:
Images
![alt text][id]
At the bottom of the document:
End a line with two or more spaces:
Roses are red,
Violets are blue.
superscript^2^
~~strikethrough~~