问题
Given a dataframe (my_data) in R such as the following
category Keyword1 Keyword2 Keyword3 Keyword4 Keyword5 Keyword6 Keyword7 Keyword8
123 0 1 1 0 0 0 0 1
155 1 0 0 0 1 0 1 1
144 0 0 1 0 0 0 1 1
123 1 1 0 0 0 0 1 1
I want to transform the dataframe by taking rows with category id values that already exist (e.g category 123) and combine them. The result should look like:
category Keyword1 Keyword2 Keyword3 Keyword4 Keyword5 Keyword6 Keyword7 Keyword8
123 1 1 1 0 0 0 0 1
155 1 0 0 0 1 0 1 1
144 0 0 1 0 0 0 1 1
How can I do this in R ?
回答1:
You can use dplyr, which is useful for many other such use cases as follows:
library(dplyr)
my_data %>% group_by(category) %>% summarise_each(funs(max))
Output is:
# A tibble: 3 × 9
category Keyword1 Keyword2 Keyword3 Keyword4 Keyword5 Keyword6 Keyword7 Keyword8
<int> <int> <int> <int> <int> <int> <int> <int> <int>
1 123 1 1 1 0 0 0 1 1
2 144 0 0 1 0 0 0 1 1
3 155 1 0 0 0 1 0 1 1
来源：https://stackoverflow.com/questions/41060599/how-to-combine-duplicate-rows-in-a-data-frame-in-r