仅在 ggplot2 的重叠处闪避或抖动

Question

我想在 ggplot2 中绘制一个图，其值与中心对齐但在重叠处避开，就像这个（在 graphpad prism 中完成）

.

我可以在 ggplot2 中使用 jitter 做什么看起来像这样

df<-data.frame(response=c(-0.3502294,0.4207441,0.1001638,-0.2401336,-0.2604142,0.4574286,
       0.755964,0.9241669,0.8212376,2.037581,0.6440635,0.2714898,1.433149,0.4627742,
       0.5639637,0.1610219,0.1516505,-1.322015,-0.2134711,0.8554756,0.400872,1.344739,
       0.3743637,0.6329151,0.1467015,0.6313575,0.3989693,0.1940468,-0.06594919,-0.1951204),
    group=c(rep("A",10),rep("B",10),rep("C",10)))

set.seed(1234)
ggplot(df,aes(group,response,fill=group))+
  geom_point(size=5,pch=21,position=position_jitter(w=.2))+
  scale_y_continuous(limits=c(-2,3))

.

如何保持点与中心对齐并仅在 ggplot2 中的重叠处闪避？

Answer 1

我对您的问题的解决方案是：

1. 将数据分为重叠点和非重叠点。这可以通过计算先前点之间的差异来完成。如果它小于某个阈值，则该点与某个点重叠，因此应在绘制该点时应用一些 zitter。否则，该点将照此绘制。
2. 使用 geom_point 分别绘制两个数据。

下面是代码，使用上面的逻辑。

library(data.table)

threshold <- 0.1

df<-data.frame(response=c(-0.3502294,0.4207441,0.1001638,-0.2401336,-0.2604142,0.4574286,
       0.755964,0.9241669,0.8212376,2.037581,0.6440635,0.2714898,1.433149,0.4627742,
       0.5639637,0.1610219,0.1516505,-1.322015,-0.2134711,0.8554756,0.400872,1.344739,
       0.3743637,0.6329151,0.1467015,0.6313575,0.3989693,0.1940468,-0.06594919,-0.1951204),
    group=c(rep("A",10),rep("B",10),rep("C",10)))

df1 <- data.table(df[order(df$group, df$response),])
df1[, diffFromLast:=response - shift(response, n=1, type="lag"), by=group]
nonZitterPoints <- df1[ is.na(diffFromLast) | (diffFromLast > threshold),]
zitterPoints <- df1[ which(diffFromLast < threshold),]

g1 <- ggplot()+
       geom_point(data=nonZitterPoints,aes(group,response,fill=group), size=5,pch=21)+
       scale_y_continuous(limits=c(-2,3))
g1

g2 <- g1 + geom_point(data=zitterPoints,aes(group,response,fill=group), size=5,pch=21, position=position_jitter(w=.2))

g2