相关性Corrplot配置

时间:2013-09-25 18:30:53

标签: r correlation r-corrplot

我是R剧本的新手: - )

我需要建立一个相关矩阵,我试图配置一些参数来调整图形。我正在使用corrplot包。

我用这种方式建立了一个corrplot矩阵:

corrplot(cor(d1[,2:14], d1[,2:14]), method=c("color"),
         bg = "white", addgrid.col = "gray50", 
         tl.cex=1, type="lower", tl.col = "black", 
         col = colorRampPalette(c("red","white","blue"))(100))

我需要在我构建的颜色矩阵内的下部矩阵中显示相关值。我怎么能这样做?

是否可以从下方矩阵中排除主对角线?在这个对角线中,我们总是有完美的相关性。

另一个疑问 - 我想用星星代替正方形来显示相关性的重要值。喜欢 (*, , *)。有可能吗?

你能帮帮我们吗?

1 个答案:

答案 0 :(得分:10)

有一点hackery你可以在一个非常相似的R包中corrgram执行此操作。这个允许您轻松定义自己的面板功能,并有助于使它们作为模板轻松查看。这是生成的一些代码和数字:

set.seed(42)
library(corrgram)

# This panel adds significance starts, or NS for not significant
panel.signif <-  function (x, y, corr = NULL, col.regions, digits = 2, cex.cor, 
                           ...) {
  usr <- par("usr")
  on.exit(par(usr))
  par(usr = c(0, 1, 0, 1))
  results <- cor.test(x, y, alternative = "two.sided")
  est <- results$p.value
  stars <- ifelse(est < 5e-4, "***", 
                  ifelse(est < 5e-3, "**", 
                         ifelse(est < 5e-2, "*", "NS")))
  cex.cor <- 0.4/strwidth(stars)
  text(0.5, 0.5, stars, cex = cex.cor)
}

# This panel combines edits the "shade" panel from the package
# to overlay the correlation value as requested
panel.shadeNtext <- function (x, y, corr = NULL, col.regions, ...) 
{
  if (is.null(corr)) 
    corr <- cor(x, y, use = "pair")
  ncol <- 14
  pal <- col.regions(ncol)
  col.ind <- as.numeric(cut(corr, breaks = seq(from = -1, to = 1, 
                                               length = ncol + 1), include.lowest = TRUE))
  usr <- par("usr")
  rect(usr[1], usr[3], usr[2], usr[4], col = pal[col.ind], 
       border = NA)
  box(col = "lightgray")
  on.exit(par(usr))
  par(usr = c(0, 1, 0, 1))
  r <- formatC(corr, digits = 2, format = "f")
  cex.cor <- .8/strwidth("-X.xx")
  text(0.5, 0.5, r, cex = cex.cor)
}

# Generate some sample data
sample.data <- matrix(rnorm(100), ncol=10)

# Call the corrgram function with the new panel functions
# NB: call on the data, not the correlation matrix
corrgram(sample.data, type="data", lower.panel=panel.shadeNtext, 
         upper.panel=panel.signif)

enter image description here

代码不是很干净,因为它主要是从包中修补功能,但它应该为你提供一个良好的开端来获得你想要的情节。可能您也可以采用corrplot包的类似方法。

更新:以下是同一个三角形上有星星和角落的版本:

panel.shadeNtext <- function (x, y, corr = NULL, col.regions, ...) 
{
  corr <- cor(x, y, use = "pair")
  results <- cor.test(x, y, alternative = "two.sided")
  est <- results$p.value
  stars <- ifelse(est < 5e-4, "***", 
                  ifelse(est < 5e-3, "**", 
                         ifelse(est < 5e-2, "*", "")))
  ncol <- 14
  pal <- col.regions(ncol)
  col.ind <- as.numeric(cut(corr, breaks = seq(from = -1, to = 1, 
                                               length = ncol + 1), include.lowest = TRUE))
  usr <- par("usr")
  rect(usr[1], usr[3], usr[2], usr[4], col = pal[col.ind], 
       border = NA)
  box(col = "lightgray")
  on.exit(par(usr))
  par(usr = c(0, 1, 0, 1))
  r <- formatC(corr, digits = 2, format = "f")
  cex.cor <- .8/strwidth("-X.xx")
  fonts <- ifelse(stars != "", 2,1)
  # option 1: stars:
  text(0.5, 0.4, paste0(r,"\n", stars), cex = cex.cor)
  # option 2: bolding:
  #text(0.5, 0.5, r, cex = cex.cor, font=fonts)
}

# Generate some sample data
sample.data <- matrix(rnorm(100), ncol=10)

# Call the corrgram function with the new panel functions
# NB: call on the data, not the correlation matrix
corrgram(sample.data, type="data", lower.panel=panel.shadeNtext, 
         upper.panel=NULL)

enter image description here

另外注释是显示重要性的另一种方式,它会将那些低于门槛而不是使用星星加粗。可能会更清楚,取决于你想要展示的内容。