如何在R中按汇总分组？ （如SQL）

本文介绍了如何在R中按汇总分组？ （如SQL）的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 29岁程序员，3月因学历无情被辞！ 我有一个数据集，我想要执行类似按汇总分组的操作，就像在SQL中对汇总值进行操作一样。I have a dataset and I want to perform something like Group By Rollup like we have in SQL for aggregate values.下面是一个可复制的例子。我知道聚合确实能很好地工作，如此处所述，但不是Below is a reproducible example. I know aggregate works really well as explained here but not a satisfactory fit for my case.year<- c('2016','2016','2016','2016','2017','2017','2017','2017')month<- c('1','1','1','1','2','2','2','2')region<- c('east','west','east','west','east','west','east','west')sales<- c(100,200,300,400,200,400,600,800)df<- data.frame(year,month,region,sales)dfyear month region sales1 2016 1 east 1002 2016 1 west 2003 2016 1 east 3004 2016 1 west 4005 2017 2 east 2006 2017 2 west 4007 2017 2 east 6008 2017 2 west 800现在我要做的是聚合（按年-月-区域求和），然后在现有数据框中添加新的聚合行，例如now what I want to do is aggregation (sum- by year-month-region) and add the new aggregate row in the existing dataframee.g. there should be two additional rows like below with a new name for region as 'USA' for the aggreagted rowsyear month region sales1 2016 1 east 4002 2016 1 west 6003 2016 1 USA 10004 2017 2 east 8005 2017 2 west 12006 2017 2 USA 2000我想出了一种方法（如下），但是我非常确定I have figured out a way (below) but I am very sure that there exists an optimum solution for this OR a better workaround than minedf1<- setNames(aggregate(df$sales, by=list(df$year,df$month, df$region), FUN=sum), c('year','month','region', 'sales'))df2<- setNames(aggregate(df$sales, by=list(df$year,df$month), FUN=sum), c('year','month', 'sales'))df2$region<- 'USA' ## added a new column- region- for total USAdf2<- df2[, c('year','month','region', 'sales')] ## reordering the columns of df2df3<- rbind(df1,df2)df3<- df3[order(df3$year,df3$month,df3$region),] ## order byrownames(df3)<- NULL ## renumbered the rows after order bydf3感谢支持！推荐答案 融化 / dcast 可以汇总。运行 dcast 之后，我们使用将月份的列中的（all） 替换为月份动物园软件包中的na.locf ：melt/dcast in the reshape2 package can do subtotalling. After running dcast we replace "(all)" in the month column with the month using na.locf from the zoo package:library(reshape2)library(zoo)m <- melt(df, measure.vars = "sales")dout <- dcast(m, year + month + region ~ variable, fun.aggregate = sum, margins = "month")dout$month <- na.locf(replace(dout$month, dout$month == "(all)", NA))给予：> dout year month region sales1 2016 1 east 4002 2016 1 west 6003 2016 1 (all) 10004 2017 2 east 8005 2017 2 west 12006 2017 2 (all) 2000 这篇关于如何在R中按汇总分组？ （如SQL）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！