干杯,我有两个数据框,具有以下结构.
DF1:
Airlines HeadQ Date Cost_Index
American PHX 07-31-2016 220
American ATL 08-31-2016 150
American ATL 10-31-2016 150
Delta ATL 10-31-2016 180
American ATL 08-31-2017 200
第二数据帧DF2具有以下结构:
DF2:
Airlines HeadQ Date
American ATL 09-30-2016
Delta ATL 03-31-2017
现在查看数据帧DF1和DF2,我想将DF1改为以下数据帧.
DF1:
Airlines HeadQ Date Cost_Index
American PHX 07-31-2016 220
American ATL 08-31-2016 0
American ATL 10-31-2016 150
Delta ATL 10-31-2016 180
American ATL 08-31-2017 200
条件是,从DF2查找DF1的航空公司和HeadQ,如果DF1 $ Date <DF2 $ Date,则将Cost_Index设为0,否则继续使用Cost_Index.
我尝试了,但未成功,:
DF1$Cost_Index <- ifelse(DF1$Airlines == DF2$Airlines & DF1$HeadQ == DF2$HeadQ
& …