来自不同数据帧的 R 中等效的 SUMIFS [重复]

Question

我一直在努力在两个数据帧之间进行条件求和。我试图重新创建数据（以我在实际工作问题中重新创建它的确切形式），所以我现在必须在 Excel 中的不同工作表之间运行一个非常简单的 sumif。我是 R 的新手，所以任何帮助将不胜感激！

x1 <- data.frame("ClientID" = c("75","85","95", "75","85","95", "75","85","95"), "Jan2014" = c(80.25, 96.47, 94.44, 85.29, 97.66, 82.33, 35.44, 55.56, 88.88), "Feb2014" = c(90.25, 46.44, 54.54, 86.29, 87.66, 52.33, 55.44, 44.56, 78.87))
column.names <- c("ClientID", "Jan2014", "Feb2014")        
ClientID <- x1$ClientID
ClientID <- unique(ClientID)
rows.no <- length(ClientID)
column.no <- length(column.names)
x2 <-   data.frame(matrix(nrow=rows.no, ncol = column.no))
colnames(x2) <- column.names
x2$ClientID <- ClientID

#I want to have the totals for each of the Jan2014 and Feb2014 columsn at the x2 data table, based on the x1 table (sumifs equivalent)

x2$Jan2014 <- 
x2$Feb2014 <- 

Answer 1

你可以这样做：

library(dplyr)
x1 %>% group_by(ClientID) %>% summarize_all(sum)

# # A tibble: 3 x 3
#   ClientID Jan2014 Feb2014
# <fctr>   <dbl>   <dbl>
# 1       75  200.98  231.98
# 2       85  249.69  178.66
# 3       95  265.65  185.74

或更一般地说（但这里的结果相同）

x1 %>% filter(ClientID %in% c(75,85,95)) %>%
  group_by(ClientID) %>%
  select(Jan2014,Feb2014) %>%
  summarize_all(sum)