将多行合二为一，R [重复]

Question

我将此数据集保存为名为 s2 的矩阵

       [,1]
0         4
0.5       1
1         6
10       61
15       28
2         8
20       25
23        1
25        4
3         3
30       44

我想按行的名称对它们进行分组，例如

         [,1]
0-10      22
10-20     89
20-30     30
30-40     48

我想知道是否有其他方法（更快，因为我的数据集比这大得多）比s[1,]=s[1,]+s2[2,]+.. 然后删除所有行？ 我尝试使用 aggregate ，并且我读到了一些关于 wordStem() 的内容，但我无处可去。 谢谢你

Answer 1

假设您的矩阵是m，您可以这样做：

library(tidyverse)

# specify your breaks for the grouping
brks = c(0,10,20,30,40)

data.frame(m) %>%                              # create a dataframe from your matrix
  rownames_to_column() %>%                     # add rownames as a column
  mutate(rowname = as.numeric(rowname)) %>%    # make that column numeric (in order to group)
  group_by(group = cut(rowname, breaks = brks, right = F)) %>%  # use your breaks to group 
  summarise(m = sum(m)) %>%                    # get the sum of values for each group
  data.frame() %>%                             # create a dataframe from tibble (in order to have rownames)
  column_to_rownames("group")                  # add rownames from your group column

#          m
# [0,10)  22
# [10,20) 89
# [20,30) 30
# [30,40) 44