使用 ggplot2 添加额外的图例信息

Question

我正在尝试向此堆叠条形图中的图例添加额外信息，但信息来自不同的数据框。我想要做的是添加一个具有实心点的图例线（在其他线下方），文本是“记录的污染物值”。我尝试了各种各样的东西，但没有任何效果。这是我到目前为止的代码：

library(ggplot2)

columns <- unlist(lapply(1:4, function(x) rep(x,32)))
labels <- c("SuperDeduper", "AdapterTrimmer", "QWindowTrim", "Reads Remaining")
diffs <- c(35666631, 36774314, 36193131, 36140701, 41584694, 33888805, 
41314700, 36430192, 36164379, 37684733, 36156080, 33443533, 28441368, 
33025395, 31980771, 29354621, 29042522, 33575127, 34144001, 35359005, 
34037116, 34030228, 30695581, 27310435, 33448959, 39547820, 37183407, 
40013726, 35679976, 33506154, 31546743, 33917856, 0, 0, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 49237692, 
50180374, 47276553, 48635427, 54147578, 39709279, 47969795, 44230737, 
52976902, 55651916, 55788100, 54082912, 50965229, 48481376, 54821029, 
55814879, 50763305, 54242897, 57001053, 54111642, 50922042, 55563781, 
48964424, 46377355, 46074343, 57514467, 51998501, 58061503, 55020584, 
54041618, 48210015, 55463206)

samps <- c("CHOR1", "CHOR10", "CHOR2", "CHOR3", "CHOR4", "CHOR5", "CHOR6", 
"CHOR7", "CHOR8", "CHOR9", "CPC1", "CPC10", "CPC11", "CPC2", 
"CPC3", "CPC4", "CPC5", "CPC6", "CPC7", "CPC8", "CPC9", "CPP1", 
"CPP2", "CPP3", "CPP4", "CPP5", "CPP6", "NB1", "NB2", "NB3", 
"NB4", "NB5", "CHOR1", "CHOR10", "CHOR2", "CHOR3", "CHOR4", "CHOR5", 
"CHOR6", "CHOR7", "CHOR8", "CHOR9", "CPC1", "CPC10", "CPC11", 
"CPC2", "CPC3", "CPC4", "CPC5", "CPC6", "CPC7", "CPC8", "CPC9", 
"CPP1", "CPP2", "CPP3", "CPP4", "CPP5", "CPP6", "NB1", "NB2", 
"NB3", "NB4", "NB5", "CHOR1", "CHOR10", "CHOR2", "CHOR3", "CHOR4", 
"CHOR5", "CHOR6", "CHOR7", "CHOR8", "CHOR9", "CPC1", "CPC10", 
"CPC11", "CPC2", "CPC3", "CPC4", "CPC5", "CPC6", "CPC7", "CPC8", 
"CPC9", "CPP1", "CPP2", "CPP3", "CPP4", "CPP5", "CPP6", "NB1", 
"NB2", "NB3", "NB4", "NB5", "CHOR1", "CHOR10", "CHOR2", "CHOR3", 
"CHOR4", "CHOR5", "CHOR6", "CHOR7", "CHOR8", "CHOR9", "CPC1", 
"CPC10", "CPC11", "CPC2", "CPC3", "CPC4", "CPC5", "CPC6", "CPC7", 
"CPC8", "CPC9", "CPP1", "CPP2", "CPP3", "CPP4", "CPP5", "CPP6", 
"NB1", "NB2", "NB3", "NB4", "NB5")

dffs <- structure(list(x = structure(1:32, .Label = c("CHOR1", "CHOR10", 
"CHOR2", "CHOR3", "CHOR4", "CHOR5", "CHOR6", "CHOR7", "CHOR8", 
"CHOR9", "CPC1", "CPC10", "CPC11", "CPC2", "CPC3", "CPC4", "CPC5", 
"CPC6", "CPC7", "CPC8", "CPC9", "CPP1", "CPP2", "CPP3", "CPP4", 
"CPP5", "CPP6", "NB1", "NB2", "NB3", "NB4", "NB5"), class = "factor"), 
    y = c(0.0544709955463634, 0.0596702158255113, 0.0586614896014222, 
    0.0624578654972305, 0.0627572173362813, 0.0652714546210198, 
    0.0720983861755616, 0.0721253780749289, 0.0663543751407387, 
    0.0550210025217426, 0.058055876946208, 0.0600278464411527, 
    0.0614602587742175, 0.0647506573410938, 0.044467464960404, 
    0.0463054497208508, 0.0540317062311753, 0.0623795178994235, 
    0.0609709990407159, 0.0660813707986263, 0.0564277955767876, 
    0.0657846664725093, 0.0702825464296669, 0.056445470816807, 
    0.0676118554533865, 0.06639558163306, 0.0850892537531267, 
    0.0593398767389062, 0.0896267454136998, 0.047540684416275, 
    0.101005522315739, 0.0840679762789124)), .Names = c("x", 
"y"), row.names = c(NA, -32L), class = "data.frame")


ggplot() + 
      geom_bar(data=data, aes(fill=columns, y=diffs, x=samps), stat="identity", position="fill") + 
      scale_fill_discrete(name="Preprocessing Steps\n(Dots are recorded\ncontaminant values)",labels=labels) +
      theme(axis.text.x = element_text(angle = 90, hjust = 1)) +
      xlab("Samples") + ylab("Fractions of all reads") +
      geom_point(data=dffs, aes(x=x,y=y))

Answer 1

我不太确定添加图例行是什么意思。您的意思是说您想要一个与预处理步骤的键共存的点的图例中的键吗？

如果是这种情况，我建议将 geom_point() 颜色映射到一个变量，该变量可以存在于任何 data.frame 之外：

ggplot() + 
  geom_bar(aes(fill=columns, y=diffs, x=samps), stat="identity", position="fill") + 
  scale_fill_discrete(name="Preprocessing Steps",labels=labels,
                      # Order set to 1 to appear before dot
                      guide = guide_legend(order = 1)) +
  theme(axis.text.x = element_text(angle = 90, hjust = 1)) +
  xlab("Samples") + ylab("Fractions of all reads") +
  # Add a colour mapping
  geom_point(data=dffs, aes(x=x,y=y, colour = "Recorded\nContaminant\nValues")) +
  # You can colour the dot how you like
  scale_colour_manual(values = "red", name = "")

这给了我以下情节：

这接近你想要的吗？