I am plotting multiple vectors in one graph with ggplot2. I have the following dataframe

So I melt the data to plot all vectors with horizontal stack bar, which is as follows:

df2<-df %>% 
  melt(id.vars = "Array") %>%
  mutate(variable = str_extract(variable, "[0-9] ")) %>%
  mutate(value = case_when(
    value == "a" ~ 1,
    value == "b" ~ 2, 
    TRUE ~ as.numeric(value)
  )) %>%
  mutate(variable = as.numeric(variable))
  
df2 %>% 
  ggplot(aes(x = Array, y = variable, group = Array, fill = value))  
  geom_col()   coord_flip()

But the x-axis is not proper, the image shows that same number of a and b in vector B has different sizes, also last single element has bigger size than first three. The problem in x-axis is easier to detect with vector B and C then Arr.

When you look at df2 variable only has 1 to 10, I cannot figure out how there are more than 50 points on x - axis.

CodePudding user response：

This is because each bar is stacking the y (variables). For each Array category, the bar is stacking from 1 to 10, the total is 1 2 ... 10 = 55, that's why you see the x-axis is over 50. That's also the reason that B and C have different sizes for a and b. The first blue blocks for B and C are: (a, a, a) = (1 2 3) = 6 and (b, b, b) = (1 2 3) = 6, they have the same size. The second blue blocks for B and C are: (b, b ,b) = (4 5 6) = 15 and (a, a) = (4 5) =9, they have different sizes.

If you want the x-axis to have range between 1-10 and the B and C have same sizes for a and b. Set your y (variable) to be a vector of 1.

df2<-df %>% 
  melt(id.vars = "Array") %>%
  mutate(value = case_when(
    value == "a" ~ 1,
    value == "b" ~ 2, 
    TRUE ~ as.numeric(value)
  )) %>%
  mutate(variable = 1) # change to 1