我有一个这样的数据框:
trans_id product_id
1 1 456
2 4 223
3 1 778
4 1 774
5 5 999
6 4 123
我需要转换它,以便所有trans_id都列为一行,如下所示:
trans_id V1 V2 V3
1 456 778 774
4 223 123
5 999
您应该添加一个辅助 ID 列。使用我的"splitstackshape"包中的getanID
很容易。由于"splitstackshape"也加载"data.table",因此使用dcast.data.table
很容易转换为宽格式:
library(splitstackshape)
dcast.data.table(
getanID(mydf, "trans_id"),
trans_id ~ .id, value.var = "product_id")
# trans_id 1 2 3
# 1: 1 456 778 774
# 2: 4 223 123 NA
# 3: 5 999 NA NA
等效的"dplyr"+"tidyr"方法如下所示:
library(dplyr)
library(tidyr)
mydf %>%
group_by(trans_id) %>%
mutate(id = sequence(n())) %>%
spread(id, product_id)
基本 R 选项将是
reshape(transform(df, N= ave(trans_id, trans_id, FUN=seq_along)),
idvar='trans_id', timevar='N', direction='wide')
# trans_id product_id.1 product_id.2 product_id.3
#1 1 456 778 774
#2 4 223 123 NA
#5 5 999 NA NA
with tidyr
library(tidyr)
t(df %>% spread(trans_id, product_id))
+1 @Ananda 马托回答tidy
和dplyr