R：堆叠 geom_bar (ggplot) 中每个 X 轴元素的多列

Question

I have data on employment in different skill classes for different provinces over time. I'd like to show the employment over time in different provinces and classes in one graph. The following figure shows what I want but only for one year (2000)

ggplot(df, aes(fill=classes, y=total/10^6, x=province)) + 
  geom_bar(position="stack", stat="identity") 

But I'd like to have each bar (showing each year) being repeated two times (in the example I have 2 years) for each province in the same graph. In other words, I'd like to show the 2001 data in the same graph as shown above beside the bars for 2000.

Here is part of the data:

df <- structure(list(year = c(2000L, 2000L, 2000L, 2000L, 2000L, 2000L, 
2000L, 2000L, 2001L, 2001L, 2001L, 2001L, 2001L, 2001L, 2001L, 
2001L), province = c("Alberta", "Alberta", "Alberta", "Alberta", 
"Manitoba", "Manitoba", "Manitoba", "Manitoba", "Alberta", "Alberta", 
"Alberta", "Alberta", "Manitoba", "Manitoba", "Manitoba", "Manitoba"
), classes = structure(c(2L, 3L, 4L, 1L, 2L, 3L, 4L, 1L, 2L, 
3L, 4L, 1L, 2L, 3L, 4L, 1L), .Label = c("[0,0.2]", "(0.2,0.4]", 
"(0.4,0.6]", "(0.6,0.8]", "(0.8,1)", "1"), class = "factor"), 
    total = c(11387250L, 4373500L, 18250L, 3215500L, 3984750L, 
    1414750L, 2000L, 1222750L, 11838250L, 4390000L, 21250L, 3272750L, 
    4019750L, 1331750L, 7750L, 1237000L)), row.names = c(NA, 
-16L), vars = c("year", "province", "classes"), drop = TRUE, class = c("grouped_df", 
"tbl_df", "tbl", "data.frame"), indices = list(3L, 0L, 1L, 2L, 
    7L, 4L, 5L, 6L, 11L, 8L, 9L, 10L, 15L, 12L, 13L, 14L), group_sizes = c(1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), biggest_group_size = 1L, labels = structure(list(
    year = c(2000L, 2000L, 2000L, 2000L, 2000L, 2000L, 2000L, 
    2000L, 2001L, 2001L, 2001L, 2001L, 2001L, 2001L, 2001L, 2001L
    ), province = c("Alberta", "Alberta", "Alberta", "Alberta", 
    "Manitoba", "Manitoba", "Manitoba", "Manitoba", "Alberta", 
    "Alberta", "Alberta", "Alberta", "Manitoba", "Manitoba", 
    "Manitoba", "Manitoba"), classes = structure(c(1L, 2L, 3L, 
    4L, 1L, 2L, 3L, 4L, 1L, 2L, 3L, 4L, 1L, 2L, 3L, 4L), .Label = c("[0,0.2]", 
    "(0.2,0.4]", "(0.4,0.6]", "(0.6,0.8]", "(0.8,1)", "1"), class = "factor")), row.names = c(NA, 
-16L), vars = c("year", "province", "classes"), drop = TRUE, class = "data.frame"))

Answer 1

Is it what you are looking for ?

ggplot(df, aes(fill=classes, y=total/10^6, x=as.factor(year))) + 
  geom_bar(position="stack", stat="identity") +
  facet_wrap(.~province)

As suggested by @user12728748, you can modify margin of the panel to make it more looks like a single plot:

ggplot(df, aes(fill=classes, y=total/10^6, x=as.factor(year))) + 
  geom_bar(position="stack", stat="identity") +
  facet_wrap(.~province)+
  theme(panel.margin = grid::unit(-1.25, "lines"))

NB: Be cautious because this trick can't be used if you set scales = free in your facet_wrap .