Observation number by group
13177
Numbering rows within groups in a data frame
142817
Probability of people attending same and different places
89726
How to count the number of unique views of a node?
77557
Observed and Observable
88569
Increment value based on grouped field
689
Using LIMIT within GROUP BY to get N results per group?
72874
GCSE: Find the number of person that will go to a party
32474
Beginner tips on using plyr to calculate year-over-year change across groups
88285
Intuition for groups
63570
Test to see what population an observation came from
132428
panel data - within-group estimate - individual fixed effects retrieved
32261
How to detect how many observations in a dataset (or if it is empty), in SAS?
84132
Number of preimages of a group element under a homomorphism.
12817
Determining true mean from noisy observations
102653
percentage count by group using dplyr
31687
Classification of groups of order 30
25421
Simple or not simple Groups