带刻面的ggplot：为每个刻面提供不同宽度的闪避效果？

Question

我想在ggplot中使用position_dodge和facet。问题是每个方面的比例不同，所以我需要为每个方面提供不同的position_dodge宽度。这可能吗？

由于我也想躲避geom_point（），因此无法自动计算此宽度。

library(data.table)
library(ggplot2)

data <- data.table(title= as.factor(c("car1", "car1", "car2", "car2", "car3") ), 
                   scenario=as.factor(c("normal", "high", "normal", "high", "normal")), 
                   price = c(1000,1000, 500,700,500), 
                   doors= c(2,2,4, 4,2) )
data.long <- melt(data, id.vars=c("title", "scenario") )
data.long[,y_value :=value/mean(value), by= .(variable) ]

#can this be used in position_dodge?
data.long[, width_dodge:=(max(value)-min(value))/10, by=variable]


ggplot(data.long ,aes(x=value, y=y_value, shape=scenario, fill=title))+
  geom_rect(aes(xmin=value-width_dodge,
                xmax=value+width_dodge,
                ymax=y_value , fill=title),
            ymin=0, position=position_dodge() )+
  scale_shape_manual(values=21:24)+
  #can position_dodge(width )  be different per facet?
  geom_point(aes(fill=title), colour="Black",position = position_dodge(width = 5) )+
  facet_wrap(~variable, scales = "free_x")

Answer 1

我使用通常的方法找到了一种解决方法：“计算外部ggplot”。可以早点考虑过这个......

library(data.table)
library(ggplot2)

data <- data.table(title= as.factor(c("car1", "car1", "car2", "car2", "car3") ), 
                   scenario=as.factor(c("normal", "high", "normal", "high", "normal")), 
                   price = c(1000,1000, 500,700,500), 
                   doors= c(2,2,4, 4,2) )
data.long <- melt(data, id.vars=c("title", "scenario") )
data.long[,y_value :=value/mean(value), by= .(variable) ]

#this can be used in value_dodgedx
data.long[, width_dodge:=(max(value)-min(value))/10, by=variable]
data.long[,`:=`( I_group=1:.N,
                 N_group=.N, 
                 group=.GRP,
                 #Here the actual dodging is done
                 value_dodgedx = value - ( (1:.N-0.5) - .N/2) *width_dodge ),
          , by=.(variable, value, y_value)]


#providing x=value_dodgedx instead of x=value
ggplot(data.long ,aes(x=value_dodgedx, y=y_value, shape=scenario, fill=title ))+
  geom_rect(aes(xmin=value_dodgedx-width_dodge/2,
                xmax=value_dodgedx+width_dodge/2,
                ymax=y_value , fill=title),
            ymin=0, position=position_dodge() )+
  scale_shape_manual(values=21:24)+
  geom_point(colour="Black")+
  facet_wrap(~variable, scales = "free_x")