R数据相关性，所有变量的排列，无重复项

我想通过排列将R中给定的data.frame中的每个变量关联起来。本例中的集合保持简单，它有4个变量：

X<-data.frame("A"=rnorm(1e3),"B"=rnorm(1e3),"C"=rcauchy(1e3),"D"=rcauchy(1e3))

不应该有重复，所以A.A或类似B.D和D.B重复的东西是不允许的

该函数是否为该函数的应用函数？如何以一种典型的方便方式实现这一点

谢谢

这里有一个方法：

X<-data.frame("A"=rnorm(1e3),"B"=rnorm(1e3),"C"=rcauchy(1e3),"D"=rcauchy(1e3))
m <- cor(X)
m[lower.tri(m, diag = TRUE)] <- NA
library(reshape2)
(df <- na.omit(melt(m)))
#    Var1 Var2       value
# 5     A    B  0.05247314
# 9     A    C -0.04440715
# 10    B    C  0.01905053
# 13    A    D  0.01920278
# 14    B    D -0.02102680
# 15    C    D  0.02793279

transform(df, Var = paste(Var1, Var2, sep = "."), Var1 = NULL, Var2 = NULL)
#          value Var
# 5   0.05247314 A.B
# 9  -0.04440715 A.C
# 10  0.01905053 B.C
# 13  0.01920278 A.D
# 14 -0.02102680 B.D
# 15  0.02793279 C.D

X<-data.frame("A"=rnorm(1e3),"B"=rnorm(1e3),"C"=rcauchy(1e3),"D"=rcauchy(1e3))
m <- cor(X)
m[lower.tri(m, diag = TRUE)] <- NA
library(reshape2)
(df <- na.omit(melt(m)))
#    Var1 Var2       value
# 5     A    B  0.05247314
# 9     A    C -0.04440715
# 10    B    C  0.01905053
# 13    A    D  0.01920278
# 14    B    D -0.02102680
# 15    C    D  0.02793279

transform(df, Var = paste(Var1, Var2, sep = "."), Var1 = NULL, Var2 = NULL)
#          value Var
# 5   0.05247314 A.B
# 9  -0.04440715 A.C
# 10  0.01905053 B.C
# 13  0.01920278 A.D
# 14 -0.02102680 B.D
# 15  0.02793279 C.D