Merge Rows within Data Frame
5136
How to sum a variable by group
46441
Combine column from multiple rows into single row
25066
Adding a new column to each element in a list of tables or data frames
56874
How can I remove all duplicates so that NONE are left in a data frame?
76717
Merging files by rows
86633
Merge records depending on common columns and specify the values which are uncommon in the last column as comma separated
132276
How to sum data.frame column values?
40942
Conditional merge/replacement in R
102396
Combine values from related rows into a single concatenated string value
104654
Transpose N rows with different columns into single column
39641
How to split a data frame?
149818
Custom Table row merge
136744
Combining multirow and multicolumn
61488
Moving columns within a data.frame() without retyping
33457
Reshaping data.frame from wide to long format
48696
Combine (rbind) data frames and create column with name of original data frames
156387
Merge two rows in SQL