Manipulating Data

General

  1. Sorting
  2. Randomizing order
  3. Converting between vector types - Numeric vectors, Character vectors, and Factors
  4. Finding and removing duplicate records
  5. Comparing vectors or factors with NA
  6. Recoding data
  7. Mapping vector values - Change all instances of value x to value y in a vector

Factors

  1. Renaming levels of a factor
  2. Re-computing the levels of factor
  3. Changing the order of levels of a factor

Data Frames

  1. Renaming columns in a data frame
  2. Adding and removing columns from a data frame
  3. Reordering the columns in a data frame
  4. Merging data frames
  5. Comparing data frames - Search for duplicate or unique rows across multiple data frames.
  6. Re-computing the levels of all factor columns in a data frame

Restructuring data

  1. Converting data between wide and long format
  2. Summarizing data - Collapse a data frame on one or more variables to find mean, count, standard deviation, standard error of the mean, and confidence intervals
  3. Converting between data frames and contingency tables - Data frames with individual cases, data frames with counts, and contingency tables

Sequential data

  1. Calculating a moving average
  2. Averaging a sequence in blocks - Convert a sequence into blocks of a given length and average within each block.
  3. Finding sequences of identical values
  4. Filling in NAs with last non-NA value