R函数，该函数合并行并引入新的合并变量

我有一个这样的数据集

ID        Brand
---      --------
1         Cokacola
2         Pepsi
3         merge with 1
4         merge with 2
5         merge with 1
6         Fanta

我想写一个R函数，它合并行并根据ID引入新变量，如下所示

ID          Brand       merge
----       --------   --------
1          Cokacola      1,3,5  
2          Pepsi         2,4   
6          Fanta         6

您的数据：

dat <- data.frame(
    id = 1:6,
    brand = c('Cokacola', 'Pepsi', 'merge with 1', 'merge with 2', 'merge with 1', 'Fanta'))

dat你可以试试

library(reshape2)
indx <- !grepl('merge', df$Brand)
df1 <- df[indx,]
val <- as.numeric(sub('[^0-9]+', '', df[!indx, 'Brand']))
ml <- melt(tapply(which(!indx), val, FUN=toString))
df2 <- merge(df1, ml, by.x='ID', by.y='Var1', all=TRUE)
df2$merge <- with(df2, ifelse(!is.na(value),
               paste(ID, value, sep=', '), ID))
df2[-3]
#   ID    Brand   merge
#1  1 Cokacola 1, 3, 5
#2  2    Pepsi    2, 4
#3  6    Fanta       6

library（重塑2）
indx
library(reshape2)
indx <- !grepl('merge', df$Brand)
df1 <- df[indx,]
val <- as.numeric(sub('[^0-9]+', '', df[!indx, 'Brand']))
ml <- melt(tapply(which(!indx), val, FUN=toString))
df2 <- merge(df1, ml, by.x='ID', by.y='Var1', all=TRUE)
df2$merge <- with(df2, ifelse(!is.na(value),
               paste(ID, value, sep=', '), ID))
df2[-3]
#   ID    Brand   merge
#1  1 Cokacola 1, 3, 5
#2  2    Pepsi    2, 4
#3  6    Fanta       6