Group variables in a dataframe R using a specific list

aggregate, grouping, list, r, variables

Solution

Here's an approach. First, use `ifelse` to assign groups to each `name`, then use `aggregate` to get the sum for each `group`.

> df$group <- with(df, ifelse(name %in% group1, "group1",
                              ifelse(name %in% group2, "group2", "group3" )))
> aggregate(value ~ group, sum, data=df)
   group value
1 group1     7
2 group2     8
3 group3     6

Problem

I have the following lists: ``` group1<-c("A", "B", "D") group2<-c("C", "E") group3<-c("F") ``` and a dataframe with values and corresponding names: ``` df <- data.frame (name=c("A","B","C","D","E","F"),value=c(1,2,3,4,5,6)) df name value 1 A 1 2 B 2 3 C 3 4 D 4 5 E 5 6 F 6 ``` I'd like to group the data based on the lists, using the name column; ``` df name value group 1 A 1 group1 2 B 2 group1 3 C 3 group2 4 D 4 group1 5 E 5 group2 6 F 6 group3 ``` and sum the values for each group. ``` df group sum 1 group1 7 2 group2 8 3 group3 6 ``` I've searched for similar posts, but failed using them for my problem.

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