如何使用多个数据集创建QQ图

Question

我想创建一个看起来像这样的情节：

！[qq] [1]

因此，该图将包含5个不同的数据集，其中每个数据集将以不同的颜色显示为线，如图所示。

现在我的代码如下：

qqunif = function(p, BH=T, MAIN = " ", SUB=" ")
{
  nn = length(p)
  xx =  -log10((1:nn)/(nn+1))
  plot( xx,  -sort(log10(p)),
        main = MAIN, sub= SUB, cex.sub=1.3,
        xlab=expression(Expected~~-log[10](italic(p))),
        ylab=expression(Observed~~-log[10](italic(p))),
        cex.lab=1.0,mgp=c(2,1,0))
  abline(0,1,col='red')
  if(BH) ## BH = include Benjamini Hochberg FDR
  {

    abline(-log10(0.05),1, col='black',lty=1)
    text(0.5,1.9 , "FDR=0.05", col = "gray60",srt=30, cex=1) 
    abline(-log10(0.10),1, col='black',lty=1)
    text(0.5, 1.6, "FDR=0.10", col = "gray60",srt=30, cex=1) 
    abline(-log10(0.25),1, col='black',lty=1)
    text(0.5, 1.2, "FDR=0.25", col = "gray60",srt=30, cex=1) 
    #legend('topleft', c("FDR = 0.05","FDR = 0.10","FDR = 0.25"),
           #col=c('black','black','black'),lty=c(1,1,1), cex=0.8)
    if (BF)
    {
      abline(h=-log10(0.05/nn), col='black') ## bonferroni
    }
  }
}

我的数据集如下：

dat1
MARKER META_pval 
rs10001545 0.8868792 
rs1000281 0.04879765 
rs10004027 0.7946071 
rs10006766 0.8806172 
rs100087 0.2386829 
rs10009948 0.8135963 
rs1001160 0.3008881 
rs1001464 0.2580996 
...

dat2
MARKER META_pval
rs100087 0.2386829
rs1001160 0.3008881
rs1001581 0.2703533
rs10028441 0.9162814
rs1003061 0.9763203
rs1006985 0.3121185
rs1010984 0.9283012
rs1012775 0.8503905
...

dat3
MARKER META_pval
rs1001581 0.2703533
rs100192 0.7959347
rs10028441 0.9162814
rs10036674 0.6278337
rs10037276 0.6222389
rs10038816 0.5864842
rs1006985 0.3121185
rs10077458 0.5905193
...

dat4
MARKER META_pval
rs10140304 0.8737664
rs10156094 0.7813031
rs10203656 0.5107122
rs10211771 0.3846588
rs10224066 0.7827652
rs10228441 0.5194636
rs10235405 0.5694455
...

对此有任何想法，也可以选择ggplot解决方案。

更新

解决方案是首先绘制“基础”图，然后为每个数据集绘制线。