The count() function in plyr does what you want: library(plyr) count(mydf, "MONTH-YEAR"). ... <看更多>

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1.1 Aggrgate Groups only Unique Group and Count · r unique occurrence of numeric groups · How to add count of unique values by group to R data. ... <看更多>

Count observations by group. #'. #' @description. #' `count()` lets you quickly count the unique values of one or more variables: #' `df %>% count(a, b)` is ... ... <看更多>

How to count the number of points in a polygon by a grouping variable in R? ... I am interested in calculating the proportion of GPS points that ... ... <看更多>