Grouping 2 levels of a factor in R
51089
Cleaning up factor levels (collapsing multiple levels/labels)
71903
Frequency count of two column in R
132574
Get the means of sub groups of means in R
81711
Joint CDF of 2 Unif(0,1) that are based on 3 other Unif(0,1)?
40352
Equal standard errors for all levels of a categorical factor in lmer
72060
Frequency counts in R
97269
Non-significant intercept in regression with a two level factor in R
62255
Notation question: Subroup generated by two elements?
125960
Factor groups of matrices
157122
How can factor-levels be automatically chosen in R to maximize the number of positive coefficients in a regression model?
123566
Recoding a variable with three levels into a dummy variable
45545
Difference between (factor|group) and (1|factor:group) specifications in lme4
8483
A Particular Two-Variable System in a Group
100267
Fit individual-level model on aggregate-level target-data
136871
R use ddply or aggregate
132210
How to assign a counter to a specific subset of a data.frame which is defined by a factor combination?
84944
How to include time factor in a mixed model (investigating the interaction between two factors and time)?