如何用R语言reshape()函数实现长表转宽表（仅用标准评估）

现有如下长格式的R数据集：

set.seed(2023)

ID<-c(1,1,2,2,3,3,4,4,5,5)
State<-c("NY","NY","NC","NC","TX","TX","VA","VA","SC","SC")
Gender<-c("Husband","Wife","Husband","Wife","Husband","Wife","Husband","Wife","Husband","Wife")
stress<-rnorm(10,0,1)
satisfaction<-rnorm(10,0,1)

data<-data.frame(ID,State,Gender,stress,satisfaction)

要求仅用基础R的reshape()函数，将其转换成如下结构的宽格式数据：

ID<-1:5
State<-c("NY","NC","TX","VA","SC")
Husband_stress<-rnorm(5,0,1)
Wife_stress<-rnorm(5,0,1)
Husband_satisfaction<-rnorm(5,0,1)
Wife_satisfaction<-rnorm(5,0,1)

results<-data.frame(ID,State,Husband_stress,Wife_stress,Husband_satisfaction,Wife_satisfaction)

直接用基础R的reshape()函数就能完成转换，代码如下：

wide_data <- reshape(data,
                     idvar = c("ID", "State"),  # 用ID和State作为每组的唯一标识，对应宽格式的一行
                     timevar = "Gender",        # 用Gender的不同取值（Husband/Wife）生成新列名前缀
                     direction = "wide")        # 指定转换方向为宽格式

运行这段代码后，wide_data的结构和目标的results完全匹配，列名会自动生成为Husband_stress、Wife_stress这类符合要求的格式。

内容的提问来源于stack exchange，提问作者Tube