separate
{dplyr}
Separate a character column into multiple columns
spread
{tidyr}
Spread a key-value pair across multiple columns
save
{base}
Writes an external representation of R objects to the specified file.
as.numeric
{base}
Coerce a vector to numeric
read_dta
{haven}
Read a .dta file (Stata data)
data.frame
{base}
Create a data.frame from vectors
n
{dplyr}
The number of observations in the current group.
summarize
NA
write_dta
NA
as.character
{base}
Coerce a vector to character
write.csv
{utils}
write a csv file to a data frame
table
{base}
Obtain frequency table of a variable/cross-tabulation of two variables
is.na
{base}
Check if a value is NA/elements of vector are NA
The end!