Question

我有2个像这样的数据帧，我想以不同的方式合并它们

A <- c("CC1_PH","CC1_PH","CC1_PH","CC2_PH","CC2_PH","CC2_PH")
B <- c ("MEAS_Length","MEAS_Breadth","MEAS_Height","MEAS_Breadth","MEAS_Height","MEAS_Length")    
df1 <- data.frame(A,B)

A <- c("CC1_PH","CC1_PH","CC2_PH","CC2_PH")
B <- c ("*","MEAS_Breadth","*","MEAS_Height")
EmpID <- c(444452,16822,339862,14828)
ManagerID <- c(11499,11499,11669,11669)
df2 <- data.frame(A,B,EmpID,ManagerID)

然后我合并这两个数据帧

df <- merge(df1,df2,by=c("A","B"),all.x=TRUE)

       A            B EmpID ManagerID
1 CC1_PH MEAS_Breadth 16822     11499
2 CC1_PH  MEAS_Height    NA        NA
3 CC1_PH  MEAS_Length    NA        NA
4 CC2_PH MEAS_Breadth    NA        NA
5 CC2_PH  MEAS_Height 14828     11669
6 CC2_PH  MEAS_Length    NA        NA

我想要的输出是

       A            B EmpID ManagerID
1 CC1_PH MEAS_Breadth 16822     11499
2 CC1_PH  MEAS_Height 444452    11499
3 CC1_PH  MEAS_Length 444452    11499
4 CC2_PH MEAS_Breadth 339862    11669
5 CC2_PH  MEAS_Height 14828     11669
6 CC2_PH  MEAS_Length 339862    11669

我想用“星号”的相应值替换NA。如何设置一个条件，当它看到“星号”时，它会返回“A”列中值的相应ManagerID和EmpID？

请提供一些有关我们如何实现这一目标的指示。

Answer 1

我们根据＆＃39; B＆＃39;中*的出现创建逻辑索引。＆＃39; df2＆＃39;的列（＆＃39; i1＆＃39;）和＆＃39; EmpID＆＃39;中的NA值＆＃39; df＆＃39; （＆＃39; I2＆＃39）。循环遍历＆lt; df＆＃39;中的相应列和＆＃39; df2＆＃39; （第3和第4），我们match＆＃39; A＆＃39;专栏＆＃39; df＆＃39;和＆＃39; df2＆＃39;，使用＆＃39; i1和＆＃39; i2＆＃39;，替换＆＃39; df＆＃39;在＆＃39; df2＆＃39;中具有相应列值的列。将输出分配回＆＃39; df＆＃39;中的第3和第4列。

i1 <-  df2$B=='*'
i2 <- is.na(df$EmpID)
df[3:4] <- Map(function(x,y) {x[i2] <- y[i1][match(df$A, 
                    df2$A[i1])][i2]
                      x}, df[3:4], df2[3:4])
df
#       A            B  EmpID ManagerID
#1 CC1_PH MEAS_Breadth  16822     11499
#2 CC1_PH  MEAS_Height 444452     11499
#3 CC1_PH  MEAS_Length 444452     11499
#4 CC2_PH MEAS_Breadth 339862     11669
#5 CC2_PH  MEAS_Height  14828     11669
#6 CC2_PH  MEAS_Length 339862     11669

在R中的列中合并具有不同值的2个数据帧

1 个答案: