厦门广告设计r⾥⾯如何实现两列数据合并为⼀列
1. library(dplyr)
2. unite(mtcars, "vs_am", vs, am)
单位边际贡献Merging Data
Adding Columns
To merge two data frames (datats) horizontally, u the merge function. In most cas, you join two data frames by one or more common key variables (i.e., an inner join).
# merge two data frames by ID
total <- merge(data frameA,data frameB,by="ID") #by指定的列中的值必须是唯⼀的，不能重复出现两⾏有相同的ID
逃出桃色房间# merge two data frames by ID and Country
total <- merge(data frameA,data frameB,by=c("ID","Country")) #by指定的列中的值必须是唯⼀的，不能
重复出现两⾏有相同的ID
Inner join:merge(df1, df2) will work for the examples becau R automatically joins the frames by common variable names, but you would most likely want to specify merge(df1, df2, by="CustomerId") to make sure that you were matching on only the fields you desired. You can also u the by.x and by.y parameters if the matching variables have different names in the different data frames.
列侬之死Outer join:merge(x = df1, y = df2, by = "CustomerId", all = TRUE) #by指定的列中的值必须是唯⼀的，不能重复出现两⾏有相同的ID
Left outer:merge(x = df1, y = df2, by = "CustomerId", all.x=TRUE) #by指定的列中的值必须是唯⼀的，不能重复出现两⾏有相同的ID Right outer:merge(x = df1, y = df2, by = "CustomerId", all.y=TRUE) #by指定的列中的值必须是唯⼀的，不能重复出现两⾏有相同的ID Cross join:merge(x = df1, y = df2, by = NULL) #by指定的列中的值必须是唯⼀的，不能重复出现两⾏有相同的ID西南大学继续教育学院
mars什么意思
>>>>>> df2 = data.frame(CustomerId=c(2,4,6),State=c(rep("Alabama",2),rep("Ohio",1)))
> df1
CustomerId Product
1 1 Toaster
2 2 Toaster
3 3 Toaster
4 4 Radio
5 5 Radio
6 6 Radio
> df2
CustomerId State
1 2 Alabama
2 4 Alabama
美国的故事3 6 Ohio
> merge(df1, df2, all=TRUE)
CustomerId Product State
1 1 Toaster <NA>
2 2 Toaster Alabama
3 3 Toaster <NA>
4 4 Radio Alabama
5 5 Radio <NA>
6 6 Radio Ohio
> merge(df1, df2, all.x=TRUE)guoxin
contract killer
CustomerId Product State
1 1 Toaster <NA>
2 2 Toaster Alabama
3 3 Toaster <NA>
4 4 Radio Alabama
5 5 Radio <NA>
6 6 Radio Ohio
> merge(df1, df2, all.y=TRUE)
CustomerId Product State
1 2 Toaster Alabama
2 4 Radio Alabama
easi
3 6 Radio Ohio
