R is a strong statistical computing environment
Thousands of packages for R
Use variable <- value
to assign a value to a variable in order to record it in memory.
Objects are created on demand whenever a value is assigned to them.
Use read.table
and write.table
to import / export data.
The function str
describes the data frame.
Use object[x, y]
to select a single element from a data frame.
Use from:to
to specify a sequence that includes the indices from from
to to
.
All the indexing and slicing that works on data frames also works on vectors.
Use #
to add comments to programs.
Use mean
, max
, min
and sd
to calculate simple statistics.
Use tapply
to calculate statistics across the groups in a data frame.
Use ggplot
to create both simple and advanced visualizations.