Including Text and Formatting

Level 2 heading added using ‘##’, deeper heading using ‘###’ and so on.

Including Code

Code chunks start with {r name, option=value} and end with. Instead of typing them manually, they can be created in RStudio using Ctrl+Alt+i command (command+option+i in mac). Optional parameters can be specified to customize the display of code chunks in the report.Some commonly used options below:

• include=TRUE (default) displays all code and results in the report, and include=FALSE runs the code but doesnot display it in the report
• echo=TRUE displays the code in the report, but not the results, and echo=FALSE hides the code in the report
• warning=TRUE/ FALSE to display warnings generated
• cache=TRUE to use knitr for caching to improve performance for time-consuming computations

Inline code can be added by enclosing in single quotes E.g. “Two plus two equals 4” displays “Two plus two equals 4”

knitr::opts_chunk$set(options) sets options globally to all code chunks unless overwritten by local options

data("cars")
head(cars)

##   speed dist
## 1     4    2
## 2     4   10
## 3     7    4
## 4     7   22
## 5     8   16
## 6     9   10

cars$time <- round(cars$dist/cars$speed,2)
cars$time

##  [1] 0.50 2.50 0.57 3.14 2.00 1.11 1.80 2.60 3.40 1.55 2.55 1.17 1.67 2.00
## [15] 2.33 2.00 2.62 2.62 3.54 1.86 2.57 4.29 5.71 1.33 1.73 3.60 2.00 2.50
## [29] 1.88 2.35 2.94 2.33 3.11 4.22 4.67 1.89 2.42 3.58 1.60 2.40 2.60 2.80
## [43] 3.20 3.00 2.35 2.92 3.83 3.88 5.00 3.40

Including Figures

Any figure produced by the code will be automatically included in the report when the code is run. You can hide accompanying code using echo=FALSE in the code chunk. Figure display options can be set in the code chunk as well as follows:

Barplot of Distance vs Speed

Including Tables

kable() function in the knitr package can be used to produce a table in the report with a matrix or data frame as input. To further customize the table with advanced fomatting options, use pander package.