问题
IN R language how to convert data1 into data2
data1 = fread("
id year cost pf loss
A 2019-02 155 10 41
B 2019-03 165 14 22
B 2019-01 185 34 56
C 2019-02 350 50 0
A 2019-01 310 40 99")
data2 = fread("
id item 2019-01 2019-02 2019-03
A cost 30 155 NA
A pf 40 10 NA
A loss 99 41 NA
B cost 185 NA 160
B pf 34 NA 14
B loss 56 NA 22
C cost NA 350 NA
C pf NA 50 NA
C loss NA 0 NA")
I try to use spread、gather、dplyr、apply..... but .....
回答1:
First get the data in long format and then get it back in wide.
library(tidyr)
data1 %>%
pivot_longer(cols = cost:loss) %>%
pivot_wider(names_from = year, values_from = value)
Note that gather and spread have been retired and replace by pivot_longer and pivot_wider.
Using data.table :
library(data.table)
dcast(melt(data1, c('id', 'year')), id+variable~year, value.var = 'value')
# id variable 2019-01 2019-02 2019-03
#1: A cost 310 155 NA
#2: A pf 40 10 NA
#3: A loss 99 41 NA
#4: B cost 185 NA 165
#5: B pf 34 NA 14
#6: B loss 56 NA 22
#7: C cost NA 350 NA
#8: C pf NA 50 NA
#9: C loss NA 0 NA
来源：https://stackoverflow.com/questions/62826796/r-spread-dataframe