How to fill a tile plot when it is facetted and with the y axis free? (ggplot2)-CodePudding

The following data frame is represented in a tile plot. Group B data has a different scale and therefore the Y-axis must be free. The plot is separated by facets according to the group. However, the group B tile plot appears as thin bands rather than looking like the group A plot. How can I make it so that, despite the Y-axis being free, the plot of group B fills all the white space as in group A?

library(ggplot2)

X <- 1:3
Y1 <- 1:3
Y2 <- seq(10, 30, 10)
Y <- c(rep(Y1,3), rep(Y2,3))
Grid <- 1:3
Group <- c("A", "B")

DF <- expand.grid(Grid = Grid,
                  X = X,
                  Group = Group)
DF$Y <- Y
DF$Grid <- NULL
DF$Z <- 1:18

ggplot(data = DF,
       aes(x = X,
           y = Y,
           fill = Z))  
  geom_tile()  
  facet_wrap(~ Group,
             scales = "free_y")

CodePudding user response：

One option to achieve your desired result would be to convert Y to a factor:

library(ggplot2)

ggplot(data = DF,
       aes(x = X,
           y = factor(Y),
           fill = Z))  
  geom_tile()  
  facet_wrap(~ Group,
             scales = "free_y")

CodePudding user response：

library(tidyverse)

DF %>% 
  complete(X = 1:3,Y = 1:30,Group = c("A","B"),fill = list(Z = NA_real_)) %>% 
  filter(!(Group == "A" & is.na(Z))) %>% 
  ggplot(aes(x = X,
           y = Y,
           fill = Z))  
  geom_tile(col = "white")  
  facet_wrap(~ Group,
             scales = "free_y")