为什么线条图无法正确分组？

Question

我有以下csv文件：

class,quantity,time
mongoclientsmall,1000,29.6
mongoclientsmall,10000,236.3
mongoclientsmall,100000,2388.4
mongoclientsmall,200000,4766.7
mongoosesmall,1000,30.7
mongoosesmall,10000,232.2
mongoosesmall,100000,2342.6
mongoosesmall,200000,4744.9
mongoclientbig,1000,31.1
mongoclientbig,10000,238.5
mongoclientbig,100000,2404.4
mongoclientbig,200000,4795.5
mongoosebig,1000,30.8
mongoosebig,10000,239
mongoosebig,100000,2356.6
mongoosebig,200000,4721

这有四个类，但是当我使用以下命令绘图时，它显示了一条包含两行的绘图，为什么？

要绘制的命令：

difftime_update <- read.table("./difftime-update.csv", header=TRUE, sep=",")

ggplot(data=difftime_update, aes(x=quantity,y=time,group=class)) +
geom_line()

Answer 1

尝试使用colour而不是group。

difftime_update %>% 
  ggplot(aes(x=quantity,y=time, colour=class)) +
  geom_line()

这对我有用。