r - ggplot 错误 : similar data graphs, 为什么不再？

Question

我正在用 ggplot 绘制一些数据。但是，我不明白我得到的数据与我可以成功绘制的数据略有不同的错误。例如，此数据图表成功:

to_graph <- structure(list(Teacher = c("BS", "BS", "FA"
), Level = structure(c(2L, 1L, 1L), .Label = c("BE", "AE", "ME", 
"EE"), class = "factor"), Count = c(2L, 25L, 28L)), .Names = c("Teacher", 
"Level", "Count"), row.names = c(NA, 3L), class = "data.frame")

ggplot(data=to_graph, aes(x=Teacher, y=Count, fill=Level), ordered=TRUE) +
       geom_bar(aes(fill = Level), position = 'fill') +
       scale_y_continuous("",formatter="percent") +
       scale_fill_manual(values = c("#FF0000", "#FFFF00","#00CC00", "#0000FF")) +
       opts(axis.text.x=theme_text(angle=45)) + 
       opts(title = "Score Distribution")

但这不会:

to_graph <- structure(list(School = c(84351L, 84384L, 84385L, 84386L, 84387L, 
84388L, 84389L, 84397L, 84398L, 84351L, 84384L, 84385L, 84386L, 
84387L, 84388L, 84389L, 84397L, 84398L, 84351L, 84386L), Level = structure(c(2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 3L, 3L), .Label = c("BE", "AE", "ME", "EE"), class = "factor"), 
    Count = c(3L, 7L, 5L, 4L, 3L, 4L, 4L, 6L, 2L, 116L, 138L, 
    147L, 83L, 76L, 81L, 83L, 85L, 53L, 1L, 1L)), .Names = c("School", 
"Level", "Count"), row.names = c(NA, 20L), class = "data.frame")

ggplot(data=to_graph, aes(x=School, y=Count, fill=Level), ordered=TRUE) +
       geom_bar(aes(fill = Level), position = 'fill') +
       scale_y_continuous("",formatter="percent") +
       scale_fill_manual(values = c("#FF0000", "#FFFF00","#00CC00", "#0000FF")) +
       opts(axis.text.x=theme_text(angle=90)) + 
       opts(title = "Score Distribution")

使用后一个代码，我收到此错误:

stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this. Error in if (!all(data$ymin == 0)) warning("Filling not well defined when ymin != 0") : missing value where TRUE/FALSE needed

有谁知道这里发生了什么？谢谢!

Answer 1

发生错误是因为您的 x 变量具有数值，而实际上您希望它们是离散的，即使用 x=factor(School) .

这样做的原因是stat_bin , geom_bar 的默认统计信息, 将尝试总结 x 的每个唯一值.当您的 x 变量是数字时，它会尝试对范围内的每个整数进行汇总。这显然不是您所需要的。

ggplot(data=to_graph, aes(x=factor(School), y=Count, fill=Level), ordered=TRUE) + 
    geom_bar(aes(fill = Level), position='fill') + 
    opts(axis.text.x=theme_text(angle=90)) + 
    scale_y_continuous("",formatter="percent") + 
    opts(title = "Score Distribution") + 
    scale_fill_manual(values = c("#FF0000", "#FFFF00","#00CC00", "#0000FF"))