Question

我被另一个R问题困在这里。我有一个以下布局的数据框，有超过2000个观察值和50列：

group <- c("X","X","X","X","Y","Y","Y","Y","Z","Z","Z","Z")
subgroup <- c("A","B","A","B","A","B","A","B","A","B","A","B")
obs1 <- c(rnorm(12,mean=10))
obs2 <- c(rnorm(12,mean=20))
e <- data.frame(group,subgroup,obs1,obs2)

我想要的是一个数据框，显示特定组x子组交互的所有观察值的总和，如下所示： column1 = group column2 = subgroup column2 = obs1，column4 = sum obs2 ....

的总和

应保留组，子组和列标签。我试过了：

for(i in levels(e$group)){test[i,]<-as.matrix(Matrix::colSums(e[,3:4]))}

但这会导致错误。可能你注意到我没有使用R编码进步：）

Answer 1

根据您的评论判断，您可能希望查看“data.table”包，它可以快速处理此类聚合并使用非常简单的语法。

在这种情况下，您可以尝试以下内容：

library(data.table)
E <- data.table(e)
E[, lapply(.SD, sum), by = c("group", "subgroup"), .SDcols = 3:4]

R根据组/子组汇总数据帧

1 个答案: