在facet_wrap中绘制平均线

我有以下数据集：

structure(list(Geschaeft = c(0.0961028525512254, 0.0753516756309475, 
0, 0.0722803347280335, 0, 0.000877706260971328), Gaststaette = c(0.0981116914423463, 
0.0789718659495242, 0.0336538461538462, 0.0905857740585774, 0, 
0.00175541252194266), Bank = c(0.100843712334271, 0.0717832023169218, 
0.00480769230769231, 0.025, 0.00571428571428572, 0.00965476887068461
), Hausarzt = c(0.0633989554037766, 0.0589573851882499, 0.0288461538461538, 
0.0217573221757322, 0.00685714285714286, 0.0128730251609128), 
    Einr..F..Aeltere = c(0.0337484933708317, 0.0550268928423666, 
    0.00480769230769231, 0, 0.00114285714285714, 0.000292568753657109
    ), Park = c(0.0738449176376055, 0.0726623913942904, 0.0625, 
    0.0846234309623431, 0.00228571428571429, 0.112053832650673
    ), Sportstaette = c(0.0449979911611089, 0.0612846503930492, 
    0.00480769230769231, 0.0619246861924686, 0.00114285714285714, 
    0), OEPNV = c(0.10847730012053, 0.089056681836988, 0.264423076923077, 
    0.135669456066946, 0, 0.185488589818607), Mangel.an.Gruenflaechen = c(0.0867818400964243, 
    0.071369466280513, 0.144230769230769, 0.117259414225941, 
    0.260571428571429, 0.186951433586893), Kriminalitaet = c(0.108316593009241, 
    0.083678113363674, 0.389423076923077, 0.139330543933054, 
    0.334857142857143, 0.216500877706261), Auslaender = c(0.00715146645239052, 
    0.0212039718659495, 0.0480769230769231, 0.0550209205020921, 
    0.0114285714285714, 0), Umweltbelastung = c(0.108879067898755, 
    0.0846607364501448, 0, 0.143828451882845, 0.376, 0.228203627852545
    ), Einr..f..Kinder = c(0.0693451185214946, 0.0825403392635499, 
    0.0144230769230769, 0.0527196652719665, 0, 0.0444704505558806
    ), Einr..f..Jugendliche = c(0, 0.0934526272238312, 0, 0, 
    0, 0.000877706260971328), count = c(1466, 1821, 81, 1491, 
    330, 793), cluster = c(1, 2, 3, 4, 5, 6)), .Names = c("Geschaeft", 
"Gaststaette", "Bank", "Hausarzt", "Einr..F..Aeltere", "Park", 
"Sportstaette", "OEPNV", "Mangel.an.Gruenflaechen", "Kriminalitaet", 
"Auslaender", "Umweltbelastung", "Einr..f..Kinder", "Einr..f..Jugendliche", 
"count", "cluster"), row.names = c(NA, -6L), class = "data.frame")

我用它排序

mdf <- melt(nbhpp[,-15], id.vars = 'cluster')
mdf <- transform(mdf, variable = reorder(variable, value, mean), y = cluster)

并绘制

ggplot(mdf, aes(x=variable, y=value, group=cluster, colour=factor(cluster))) + 
  geom_line() + 
  scale_y_continuous('Anteile', formatter = "percent") +
  scale_colour_hue(name='Cluster') +
  xlab('Infrastrukturmerkmal') +
  theme_bw() +
  opts(axis.text.x = theme_text(angle=90, hjust=1), legend.position = "none") +
  facet_wrap(~cluster, ncol=3)

如果我理解正确的话，变换函数按平均值对数据进行排序。但如何才能将这些平均值作为灰线包含到每个图中呢？

感谢您的帮助

UPDATE:

只是为了澄清：

如果我看一下重新排序语句的输出

with(mdf, reorder(variable, value, mean))

比我得到以下属性：

attr(,"scores")
   Einr..f..Jugendliche        Einr..F..Aeltere              Auslaender            Sportstaette 
             0.01572172              0.01583642              0.02381364              0.02902631 
               Hausarzt                    Bank               Geschaeft         Einr..f..Kinder 
             0.03211500              0.03630061              0.04076876              0.04391644 
            Gaststaette                    Park                   OEPNV Mangel.an.Gruenflaechen 
             0.05051310              0.06799505              0.13051918              0.14452739 
        Umweltbelastung           Kriminalitaet 
             0.15692865              0.21201772 

它们在图中从左（最低）到右（最高）排序。 问题是，如何用这些属性画一条线......

编辑后的答案

要添加一条包含聚类平均值的线，您需要构造一个data.frame包含数据。您可以从中提取值mdf:

meanscores <- attributes(mdf$variable)$scores
meandf <- data.frame(
  variable = rep(names(meanscores), 6),
  value    = rep(unname(meanscores), 6),
  cluster  = rep(1:6, each=14)
  )

然后使用绘图geom_line:

ggplot(mdf, aes(x=variable, y=value, group=cluster, colour=factor(cluster))) + 
  geom_line() + 
  scale_y_continuous('Anteile', formatter = "percent") +
  scale_colour_hue(name='Cluster') +
  xlab('Infrastrukturmerkmal') +
  theme_bw() +
  opts(axis.text.x = theme_text(angle=90, hjust=1), legend.position = "none") +
  facet_wrap(~cluster, ncol=3) +
  geom_line(data=meandf, aes(x=variable, y=value), colour="grey50")

原答案

我最初的解释是你想要一条具有整体平均值的水平线。

只需添加一个geom_hline图层到你的图上，并映射yintercept to mean(value):

ggplot(mdf, aes(x=variable, y=value, group=cluster, colour=factor(cluster))) + 
  geom_line() + 
  scale_y_continuous('Anteile', formatter = "percent") +
  scale_colour_hue(name='Cluster') +
  xlab('Infrastrukturmerkmal') +
  theme_bw() +
  opts(axis.text.x = theme_text(angle=90, hjust=1), legend.position = "none") +
  facet_wrap(~cluster, ncol=3) +
  geom_hline(aes(yintercept=mean(value)), colour="grey50")