我正在尝试使用ggplot在r中绘制线图。不幸的是,图例没有显示。谁能帮我吗?
我的代码如下:
dfdatavgsM=data.frame(datum,avgsätzegespMT,avgsätzegespML)
ggplot(data = dfdatavgsM,aes(x=datum,color=Wettbewerbsart))
+ geom_line(data=dfdatavgsM,aes(y = avgsätzegespML),color="red")
+ geom_line(data=dfdatavgsM,aes(y = avgsätzegespMT),color="blue")
+ geom_vline(xintercept=2011,size = 0.6)
+ scale_y_continuous(name="Anzahl an Sätzen")
+ scale_x_datetime(name = "Saison",date_breaks = ("2 year"),date_labels = "%Y")
+ ggtitle("Wettbewerbsintensität in Spielen mit |∆TTR| ≤ 118") + theme(panel.background = element_rect(fill = "white",colour = "black"))
+ theme(panel.grid.major = element_line(size = 0.25,linetype = 'solid',colour = "light grey")) + theme(axis.ticks = element_line(size = 1))