R中按组分别计算总和

Question

说，我有数据集。

df=structure(list(ItemRelation = c(13250L, 13250L, 13250L, 13250L, 
13250L, 13250L, 13250L, 13250L, 13250L, 13250L, 13250L, 13250L, 
1300L, 1300L, 1300L, 1300L, 1300L, 1300L, 1300L, 1300L, 1300L, 
1300L, 1300L, 1300L), SaleCount = c(354L, 679L, 397L, 473L, 614L, 
404L, 127L, 434L, 786L, 127L, 434L, 786L, 354L, 679L, 397L, 473L, 
614L, 404L, 127L, 434L, 786L, 127L, 434L, 786L), DocumentNum = c(336L, 
336L, 336L, 336L, 336L, 336L, 336L, 336L, 336L, 336L, 336L, 336L, 
335L, 335L, 335L, 335L, 335L, 335L, 335L, 335L, 335L, 335L, 335L, 
335L), IsPromo = c(0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 1L, 1L, 
1L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 1L, 1L, 1L)), .Names = c("ItemRelation", 
"SaleCount", "DocumentNum", "IsPromo"), class = "data.frame", row.names = c(NA, 
-24L))

有变量 ispromo。它只需要值 0 和 1。所以，我必须分别为每个组计算销售计数的总和，但仅限于 1 类 ispromo。组是 ItemRelation +SaleCount +DocumentNum

我该怎么做？

期望的输出

ItemRelation    DocumentNum sum1
13250            336       1347
1300             335       1347

Answer 1

使用 dplyr:

library(dplyr)

df %>% 
  group_by(ItemRelation, DocumentNum) %>% 
  filter(IsPromo == 1) %>% 
  summarise(sum1 = sum(SaleCount))

# A tibble: 2 x 3
# Groups:   ItemRelation [?]
  ItemRelation DocumentNum  sum1
         <int>       <int> <int>
1         1300         335  1347
2        13250         336  1347

Answer 2

这是使用 aggregate

的互补基础 R 解决方案

aggregate(SaleCount ~ ItemRelation + DocumentNum, subset(df, IsPromo == 1), sum)
#  ItemRelation DocumentNum SaleCount
#1         1300         335      1347
#2        13250         336      1347

R中按组分别计算总和

calculation sum separately by groups in R

r

plyr

lapply

dplyr