使用ggplot在同一直方图中绘制两个变量

Question

我有一个数据框，我想通过使用ggplot来制作直方图。我希望在x轴和y轴上有森林，农业，建筑，其他和水，对于每个土地使用都会有委任和遗漏错误。有人可以帮我吗。谢谢

 dput(n)
    structure(c(90.49964814, 36.77437804, 18.61958266, 57.14285714, 
    20, 100, 9.53346856, 45.63106796, 0, 0), .Dim = c(2L, 5L), .Dimnames = list(
        c("Omission Error", "Comission Error"), c("Forest", "Agriculture", 
        "Built-up", "Other", "Water")))

Answer 1

或者这种替代方案适合吗？

library(reshape2); library(ggplot2)
df2 <- melt(df, id.var=Forest)
#                 X1          X2      value
# 1   Omission Error      Forest  90.499648
# 2  Comission Error      Forest  36.774378
# 3   Omission Error Agriculture  18.619583
# 4  Comission Error Agriculture  57.142857
# 5   Omission Error    Built-up  20.000000
# 6  Comission Error    Built-up 100.000000
# 7   Omission Error       Other   9.533469
# 8  Comission Error       Other  45.631068
# 9   Omission Error       Water   0.000000
# 10 Comission Error       Water   0.000000

ggplot(df2, aes(x=X2, y=value)) + geom_bar(stat="identity") + facet_grid(X1~.)

Answer 2

使用ggplot，当你想要共享一个维度（例如，x轴，颜色）时，你需要它们在一列中。因此，我们首先使用reshape2::melt

将您的数据重新整形为长格式

library(reshape2)
library(scales) # for percent formatter
longdf <- melt(n)
names(longdf) <- c("Error", "Land_Use", "Measure")

然后绘图很容易。

ggplot(longdf, aes(x = Land_Use, y = Measure / 100, fill = Error)) +
    geom_bar(stat = "identity", position = "dodge") +
    scale_y_continuous(labels = percent_format()) +
    labs(x = "Land Use", y = "Error Percent", fill = "Error Type")