r - 在R中合并具有特定条件的两个数据帧

Question

我有两个数据框:

df1
Syllable Duration Pitch
@         0.08    93
@         0.05    107
@         0.13    56
@         0.07    95
@         0.07    123

df2
Syllable Duration 
@        0.08 
@        0.05 
@        0.07
@        0.07 

我想将它们合并到另一个数据框中:

df3
Syllable Duration Pitch
@        0.08     93
@        0.05     107
@        0.07     95
@        0.07     123

问题是我重复了 Syllable 和 Duration 值。我试过这段代码，但它给了我不正确的音调:

df3 <- merge(df2, df1[!duplicated(df1$Syllable),], by="Syllable")

df3
Syllable Duration Pitch
@        0.08     93
@        0.05     93
@        0.07     93
@        0.07     93

Answer 1

使用 data.table 你可以:

library("data.table")
df1 <- fread(
"Syllable Duration Pitch
@ 0.08 93
@ 0.05 107
@ 0.13 56
@ 0.07 95
@ 0.07 123")
df2 <- fread(
"Syllable Duration 
@ 0.08 
@ 0.05 
@ 0.07
@ 0.07")
merge(df1, unique(df2))
# > merge(df1, unique(df2))
#    Syllable Duration Pitch
# 1:        @     0.05   107
# 2:        @     0.07    95
# 3:        @     0.07   123
# 4:        @     0.08    93

或不排序:

merge(df1, unique(df2), sort=FALSE)
# > merge(df1, unique(df2), sort=FALSE)
#    Syllable Duration Pitch
# 1:        @     0.08    93
# 2:        @     0.05   107
# 3:        @     0.07    95
# 4:        @     0.07   123

这最后一个是一样的:

df1[unique(df2), on=c("Syllable", "Duration")]
# > df1[unique(df2), on=c("Syllable", "Duration")]
#    Syllable Duration Pitch
# 1:        @     0.08    93
# 2:        @     0.05   107
# 3:        @     0.07    95
# 4:        @     0.07   123

基于R:

df1 <- read.table(header=TRUE, text=
"Syllable Duration Pitch
@         0.08    93
@         0.05    107
@         0.13    56
@         0.07    95
@         0.07    123")

df2 <- read.table(header=TRUE, text=
"Syllable Duration 
@        0.08 
@        0.05 
@        0.07
@        0.07 ")
merge(df1, unique(df2))
merge(df1, unique(df2), sort=FALSE)