Coerce multiple columns to factors at once

by

Choose some columns to coerce to factors:

cols <- c("A", "C", "D", "H")

Use lapply() to coerce and replace the chosen columns:

data[cols] <- lapply(data[cols], factor)  ## as.factor() could also be used

Check the result:

sapply(data, class)
#        A         B         C         D         E         F         G 
# "factor" "integer"  "factor"  "factor" "integer" "integer" "integer" 
#        H         I         J 
# "factor" "integer" "integer"

More Related Contents:

  1. Drop unused factor levels in a subsetted data frame
  2. Count number of rows within each group
  3. Why is it not advisable to use attach() in R, and what should I use instead?
  4. Create an empty data.frame
  5. Merging a lot of data.frames [duplicate]
  6. Select rows with min value by group
  7. Shifting non-NA cells to the left
  8. Omit rows containing specific column of NA
  9. Repeat rows of a data.frame N times
  10. For each row in an R dataframe
  11. Replace all occurrences of a string in a data frame
  12. Convert Named Character Vector to data.frame
  13. How to add a cumulative column to an R dataframe using dplyr?
  14. Same function over multiple data frames in R
  15. Create empty data frame with column names by assigning a string vector? [duplicate]
  16. Add extra level to factors in dataframe
  17. Dataframe create new column based on other columns
  18. What is about the first column in R’s dataset mtcars?
  19. Last Observation Carried Forward In a data frame? [duplicate]
  20. Determine the data types of a data frame’s columns
  21. finding close match from data frame 1 in data fame 2
  22. Combine several data frames in the global environment by row (rbind)
  23. Changing Million/Billion abbreviations into actual numbers? ie. 5.12M -> 5,120,000 [duplicate]
  24. Extract text after “/” in a data frame column
  25. use multiple columns as variables with sapply
  26. Merge overlapping ranges into unique groups, in dataframe
  27. Deleting specific rows from a data frame
  28. Reshape a dataframe to long format with multiple sets of measure columns [duplicate]
  29. Count number of non-NA values for every column in a dataframe [duplicate]
  30. R how can I calculate difference between rows in a data frame

Leave a Comment