2016-09-14 76 views
0

我有一个数据框,我想找到哪组变量共享最高的相关性。例如:一组高度相关的变量

mydata <- structure(list(V1 = c(1L, 2L, 5L, 4L, 366L, 65L, 43L, 456L, 876L, 78L, 687L, 378L, 378L, 34L, 53L, 43L), 
         V2 = c(2L, 2L, 5L, 4L, 366L, 65L, 43L, 456L, 876L, 78L, 687L, 378L, 378L, 34L, 53L, 41L), 
         V3 = c(10L, 20L, 10L, 20L, 10L, 20L, 1L, 0L, 1L, 2010L,20L, 10L, 10L, 10L, 10L, 10L), 
         V4 = c(2L, 10L, 31L, 2L, 2L, 5L, 2L, 5L, 1L, 52L, 1L, 2L, 52L, 6L, 2L, 1L), 
         V5 = c(4L, 10L, 31L, 2L, 2L, 5L, 2L, 5L, 1L, 52L, 1L, 2L, 52L, 6L, 2L, 3L)), 
        .Names = c("V1", "V2", "V3", "V4", "V5"), 
        class = "data.frame", row.names = c(NA,-16L)) 

我可以计算相关与找到具有高于阈值corelations每对为:

var.corelation <- cor(as.matrix(mydata), method="pearson") 

fin.corr = as.data.frame(as.table(var.corelation)) 
combinations_1 = combn(colnames(var.corelation) , 2 , FUN = function(x) paste(x , collapse = "_")) 
fin.corr = fin.corr[ fin.corr$Var1 != fin.corr$Var2 , ] 

fin.corr = fin.corr [order(fin.corr$Freq, decreasing = TRUE) , ,drop = FALSE] 

fin.corr = fin.corr[ paste(fin.corr$Var1 , fin.corr$Var2 , sep = "_") %in% combinations_1 , ] 

fin.corr <- fin.corr[fin.corr$Freq > 0.62, ] 

fin.corr <- fin.corr[order(fin.corr$Var1, fin.corr$Var2), ] 
fin.corr 

直到现在的输出是:

Var1 Var2  Freq 
V1 V2  0.9999978 
V3 V4  0.6212136 
V3 V5  0.6220380 
V4 V5  0.9992690 

这里V1V2形式一组而其他V3,V4,V5形成另一组,其中每对变量bles的相关性高于阈值。我想把这两组变量作为一个列表。例如

list(c("V1", "V2"), c("V3", "V4", "V5")) 
+1

我想你可以将你的方法建立在一个更干净的过程上,从相关性中提取组。我可以看到两种可能性:聚类相关矩阵(例如检查“hclust”(例如:http://research.stowers-institute.org/efg/R/Visualization/cor-cluster/)。第二个可能性:因子分析并利用因子) –

+0

谢谢埃里克!我通过链接张贴问题。我的层次聚类没有工作,因为我错过了步骤'as.dist'将相关矩阵转换为dist对象,我的(错误)假设是他们是一样的,谢谢你的评论和答复,我已经接受了。 – discipulus

回答

2

使用图论和igraph包得出答案。

var.corelation <- cor(as.matrix(mydata), method="pearson") 

library(igraph) 
# prevent duplicated pairs 
var.corelation <- var.corelation*lower.tri(var.corelation) 
check.corelation <- which(var.corelation>0.62, arr.ind=TRUE) 

graph.cor <- graph.data.frame(check.corelation, directed = FALSE) 
groups.cor <- split(unique(as.vector(check.corelation)),   clusters(graph.cor)$membership) 
lapply(groups.cor,FUN=function(list.cor){rownames(var.corelation)[list.cor]}) 

返回:

$`1` 
[1] "V1" "V2" 

$`2` 
[1] "V3" "V4" "V5" 

我还要检查我的意见,这对我带来更好的见解,你可能有比你(任意)割点较少,但真正与群集关联的相关性。