R中条形图中的着色图例

Question

I'm faily new to R and do need some help in manipulating my graph. I'm trying to compare actual and forecast figures, but cannot get the coloring of the legends right. The data looks like this:

hierarchy    Actual  Forecast
     <fctr>     <dbl>     <dbl>
1         E      9313      5455
2         K      6257      3632
3         O      7183      8684
4         A      1579      6418
5         S      8755      0149
6         D      5897      7812
7         F      1400      8810
8         G      4960      5710
9         R      3032      0412

And the code looks like this:

ggplot(sam4, aes(hierarchy))+ theme_bw()  + 
  geom_bar(aes(y = Actual, colour="Actual"),fill="#66FF33", stat="identity",position="dodge", width=0.40) +
  geom_bar(aes(y = Forecast, colour="Forecast"), fill="#FF3300", stat="identity",position="dodge", width=0.2)

The graph ends up looking like this:

Answer 1

I believe your problem is that your data is not formatted well to use ggplot. You want to tidy up your dataframe first. Check out http://tidyr.tidyverse.org/ to get familiar with the concept of tidy data.

Using the tidyverse (ggplot is part of it), I tidied up your data and I believe got the plot you want.

library(tidyverse) #includes ggplot
newdata <- gather(sam4, actualorforecast, value, -hierarchy)
ggplot(newdata, aes(x = hierarchy)) +
    theme_bw() +
    geom_bar(aes(y = value, fill = actualorforecast), 
             stat = "identity", 
             width = ifelse(newdata$actualorforecast == "Actual", .4, .2),
             position = "dodge") +
    scale_fill_manual(values= c(Actual ="#66FF33", Forecast="#FF3300"))