Before we Start
|
|
Introduction to R
|
Access individual values by location using [] .
Access slices of data using [low:high] .
Access arbitrary sets of data using [c(...)] .
Use logical operations and logical vectors to access subsets of data.
|
Starting with Data
|
|
Introducing dplyr and tidyr
|
Use the dplyr package to manipulate dataframes.
Use select() to choose variables from a dataframe.
Use filter() to choose data based on values.
Use group_by() and summarize() to work with subsets of data.
Use mutate() to create new variables.
Use the tidyr package to change the layout of dataframes.
Use gather() to go from wide to long format.
Use spread() to go from long to wide format.
|
Data visualisation with ggplot2
|
ggplot2 is a flexible and useful tool for creating plots in R.
The data set and coordinate system can be defined using the ggplot function.
Additional layers, including geoms, are added using the + operator.
Boxplots are useful for visualizing the distribution of a continuous variable.
Barplot are useful for visualizing categorical data.
Faceting allows you to generate multiple plots based on a categorical variable.
|