How to cast and melt a data frame with 2 unique IDs
97533
How to find differences in elements of 2 data frames based on 2 unique identifiers
21016
How to initialize empty data frame (lot of columns at the same time) in R
37373
Reshape three column data frame to matrix ("long" to "wide" format)
62998
How to match multiple copies of a value?
4982
How to combine multiple conditions to subset a data-frame using "OR"?
35506
remove duplicate from list and create non-duplicate id set
56874
How can I remove all duplicates so that NONE are left in a data frame?
44310
Create unique number from 2 numbers
5292
Convert data.table to data.frame (i.e. undo setDT)
102482
Transpose a data frame
152949
Reshape multiple value columns to wide format
21454
Adding an identity to an existing column
14066
Pivoting of data using two columns
82140
How do I delete rows in a data frame?
106494
Create a data.frame where a column is a list
32937
Combine two data frames by rows (rbind) when they have different sets of columns
138925
How to convert multiple duplicate columns as single row with appreciated values