在ggplot2热图中区分组之间的构面

Question

I have this data frame:

gene_symbol<-c("DADA","SDAASD","SADDSD","SDADD","ASDAD","XCVXCVX","EQWESDA","DASDADS","SDASDASD","DADADASD","sdaadfd","DFSD","SADADDAD","SADDADADA","DADSADSASDWQ","SDADASDAD","ASD","DSADD")
panel<-c("growth","growth","growth","growth","big","big","big","small","small","dfgh","DF","DF","DF","DF","DF","gh","DF","DF")
ASDDA<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDb<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf1<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf2<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf3<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf4<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf5<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDA1<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDb1<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf1<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf11<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf21<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf31<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf41<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
ASDDAf51<-c("normal","over","low","over","normal","over","low","over","normal","over","DF","DF","DF","DF","DF","DF","DF","DF")
Gene_states22 <- data.frame(gene_symbol, panel, ASDDA, ASDDb, ASDDAf, ASDDAf1, ASDDAf2, 
                            ASDDAf3, ASDDAf4, ASDDAf5, ASDDA1, ASDDb1, ASDDAf1, ASDDAf11,
                            ASDDAf21, ASDDAf31, ASDDAf41, ASDDAf51)

And I create 6 heatmaps with:

library(plotly)
library(ggplot2); library(reshape2)
HG3 <- split(Gene_states22[,1:15], Gene_states22$panel)
HG4 <- melt(HG3, id.vars= c("gene_symbol","panel"))
HG4 <- HG4[,-5]
HG5 <- split(HG4, HG4$panel)
pp <- ggplot(HG4, 
       aes(gene_symbol,variable)) + 
  geom_tile(aes(fill = value),
            colour = "grey50") + 
  facet_grid(~panel, scales = "free") +

  # it looks like you have more colours than values here.
  # I recommend using a named vector in this case, so that 
  # the same value always maps to the same colour.
  # e.g. values = c("DF" = "white", "low" = "red", ...)
  scale_fill_manual(values = c("white", "red", "blue", "black", "yellow", "green", "brown")) +

  labs(title = "Heatmap", x = "gene_symbol", y = "sample", fill = "value") +
  guides(fill = FALSE)+
  theme(panel.background = element_rect(fill = NA),
        panel.spacing = unit(0, "lines"),
        strip.placement = "outside")

ggplotly(pp,
         width = 1350, height = 600) %>%
  # note: specifying width / height in layout() has been deprecated
  # in recent versions of plotly. when I used it that way, I got
  # a warning to specify it within ggplotly() instead.
  layout(autosize = F, 
         hoverlabel = list(bgcolor = "white",
                           font = list(family = "sans serif", size = 9, color = "black"))) 

As you can see from the picture below my heatmap is separated into 6 groups. and the name of each group is placed accordingly on this grey zone

I would like somehow to separate this grey zone maybe by 6 different colors instead of only grey or add space between each separated group in order to distinguish better. Of course I would be open to other suggestions.

Answer 1

You could add more space between each facet. In fact, in your code, you are setting that space to 0, which does not seem to fit your desire.

Try this:

 ggplot(HG4, aes(gene_symbol,variable)) + 
       geom_tile(aes(fill = value),
        colour = "grey50") + 
      facet_grid(~panel, scales = "free") +
      scale_fill_manual(values = c("white", "red", "blue", "black", "yellow", "green", "brown")) +
      labs(title = "Heatmap", x = "gene_symbol", y = "sample", fill = "value") +
      guides(fill = FALSE)+
      theme(panel.background = element_rect(fill = NA),
            panel.spacing = unit(0.5, "lines"), ## It was here where you had a 0 for distance between facets. I replaced it by 0.5 .
            strip.placement = "outside")