按多列分组并对其他多列求和 [英] Group by multiple columns and sum other multiple columns

问题描述

我有一个包含大约 200 列的数据框，其中我想按前 10 个左右的因素对表格进行分组，并对其余列求和.

I have a data frame with about 200 columns, out of them I want to group the table by first 10 or so which are factors and sum the rest of the columns.

我有我想要分组的所有列名的列表以及我想要聚合的所有列的列表.

I have list of all the column names which I want to group by and the list of all the cols which I want to aggregate.

我正在寻找的输出格式需要是具有相同列数的相同数据帧，只是组合在一起.

The output format that I am looking for needs to be the same dataframe with same number of cols, just grouped together.

是否有使用包 data.table、plyr 或任何其他包的解决方案?

Is there a solution using packages data.table, plyr or any other?

推荐答案

data.table 方式是:

DT[, lapply(.SD,sum), by=list(col1,col2,col3,...)]

或

DT[, lapply(.SD,sum), by=colnames(DT)[1:10]]

其中 .SD 是 (D)data 排除 组列的 (S) 子集.(另外:如果您需要一般地引用组列，它们在 .BY 中.)

where .SD is the (S)ubset of (D)ata excluding group columns. (Aside: If you need to refer to group columns generically, they are in .BY.)

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