问题描述
我有一个包含4个变量的数据框，其中一个是时间，两个是速度，最后一个是降水。速度和降水之间的尺度完全不同。我想绘制两个Y轴，一个用于速度，一个完全不同的Y轴用于降水。另外，是否可以帮助我手动重新订购图例？
data <- structure(list(Time = structure(c(147L,25L,44L,20L,7L,74L,51L,156L,62L,115L),.Label = c("06:00:00","06:05:00","06:10:00","06:15:00","06:20:00","06:25:00","06:30:00","06:35:00","06:40:00","06:45:00","06:50:00","06:55:00","07:00:00","07:05:00","07:10:00","07:15:00","07:20:00","07:25:00","07:30:00","07:35:00","07:40:00","07:45:00","07:50:00","07:55:00","08:00:00","08:05:00","08:10:00","08:15:00","08:20:00","08:25:00","08:30:00","08:35:00","08:40:00","08:45:00","08:50:00","08:55:00","09:00:00","09:05:00","09:10:00","09:15:00","09:20:00","09:25:00","09:30:00","09:35:00","09:40:00","09:45:00","09:50:00","09:55:00","10:00:00","10:05:00","10:10:00","10:15:00","10:20:00","10:25:00","10:30:00","10:35:00","10:40:00","10:45:00","10:50:00","10:55:00","11:00:00","11:05:00","11:10:00","11:15:00","11:20:00","11:25:00","11:30:00","11:35:00","11:40:00","11:45:00","11:50:00","11:55:00","12:00:00","12:05:00","12:10:00","12:15:00","12:20:00","12:25:00","12:30:00","12:35:00","12:40:00","12:45:00","12:50:00","12:55:00","13:00:00","13:05:00","13:10:00","13:15:00","13:20:00","13:25:00","13:30:00","13:35:00","13:40:00","13:45:00","13:50:00","13:55:00","14:00:00","14:05:00","14:10:00","14:15:00","14:20:00","14:25:00","14:30:00","14:35:00","14:40:00","14:45:00","14:50:00","14:55:00","15:00:00","15:05:00","15:10:00","15:15:00","15:20:00","15:25:00","15:30:00","15:35:00","15:40:00","15:45:00","15:50:00","15:55:00","16:00:00","16:05:00","16:10:00","16:15:00","16:20:00","16:25:00","16:30:00","16:35:00","16:40:00","16:45:00","16:50:00","16:55:00","17:00:00","17:05:00","17:10:00","17:15:00","17:20:00","17:25:00","17:30:00","17:35:00","17:40:00","17:45:00","17:50:00","17:55:00","18:00:00","18:05:00","18:10:00","18:15:00","18:20:00","18:25:00","18:30:00","18:35:00","18:40:00","18:45:00","18:50:00","18:55:00","19:00:00"),class = "factor"),variable = structure(c(3L,1L,3L,2L,2L),.Label = c("Ground Speed(km/h)","Precipitation(cm/h)","Predicted Speed(km/h)"),value = c(105.507629394531,101.367,105.266487121582,3.0613,99.758,106.194,106.969375610352,107.803,0)),row.names = c(NA,-10L),class = "data.frame")
我在下面尝试了此代码：
data %>%
gather(variable,speed,-Time) %>%
ggplot(aes(x = Time,y = speed,group = variable,colour = variable,linetype=variable)) +
geom_line()+
theme(axis.text.x = element_text(angle = 90,vjust = 0.5,hjust=1)) +
scale_linetype_manual(values=c("dashed","dotted","solid"))+
scale_x_discrete(breaks=c("07:00:00","18:00:00"),labels=c("7:00","10:00","13:00","15:00","18:00"))+
xlab("Time")+
ylab("Speed(km/h)")+
theme(text=element_text(size=10,family="Cambria"))+
theme(panel.grid.major = element_blank(),panel.grid.minor = element_blank(),panel.border = element_rect(colour = "black",fill=NA,size=1),panel.background = element_blank())+
theme(legend.position = "bottom")+scale_size(range=c(1,9),guide="none")+
theme(legend.key.size = unit(0.45,"cm"))+
scale_y_continuous("Precipitation(cm/h)",sec.axis = sec_axis(~.,name = "Precipitation"))
解决方法
针对提供的评论，也许您可以考虑将facet_wrap与scales="free"一起使用。
data %>%
ggplot(aes(x = Time,y = value,colour = variable)) +
geom_line(group = 1)+
facet_wrap(~variable,scales = "free")+
theme(axis.text.x = element_text(angle = 90,vjust = 0.5,hjust=1))
由reprex package（v0.3.0）于2020-08-11创建
,嗯，您确实需要进行转换，但是您可以做到这一点。我选择* 30作为转换，但这只是一个猜测。我还添加了如何通过重新排列ggplot中的因素来重新排列图例，并消除了一些不必要的东西。
library(dplyr)
library(ggplot2)
data$variable <-
forcats::fct_relevel(data$variable,"Ground Speed(km/h)","Predicted Speed(km/h)","Precipitation(cm/h)" )
data <-
data %>%
mutate(newvalue = case_when(
variable == "Precipitation(cm/h)" ~ value * 30,TRUE ~ value)
)
ggplot(data,aes(x = Time,y = newvalue,group = variable,color = variable,linetype = variable)) +
geom_line() +
scale_y_continuous(sec.axis = sec_axis(~. / 30,name = "Precipation cm/hr")) +
theme(axis.text.x = element_text(angle = 90,hjust=1)) +
xlab("Time") +
ylab("Speed(km/h)") +
theme(text=element_text(size=10))+
theme(panel.grid.major = element_blank(),panel.grid.minor = element_blank(),panel.border = element_rect(colour = "black",fill=NA,size=1),panel.background = element_blank()) +
theme(legend.position = "bottom") +
theme(legend.key.size = unit(0.45,"cm"))
