Preserve structure when saving data to files in R

Writing data to a file using write.csv failes to retain column data types. A better way to save/restore data objects to/from files is by using RDS and RData.

We can write/read a single data object, multiple objects, or an entire workspace. Here’s a simple example:

# save data object to file
saveRDS(df, file = 'df.rds')
# restore object 
readRDS(file = 'df.rds')
# restore object under a different name 
new_df <- readRDS(file = 'df.rds')

# save multiple data objects to file
save(df1, df2, file = 'two_dfs.rda')
# restore multiple objects 
load(file = 'two_dfs.rda')

Note: *.rda = *.RData
You can use either file extension with save and load. e.g. save(df1, df2, file = 'two_dfs.RData').

Reference

For more on RDS and RData, including saving an entire workspace, see: http://www.sthda.com/english/wiki/saving-data-into-r-data-format-rds-and-rdata