ggplot2中的兩個美學和幾何圖例的傳說

Question

我正在嘗試爲下圖繪製一個圖例，其中虛線跟着A，虛線跟着B，它不能正確顯示。由於我有兩種美學，它有時只顯示一種線條類型或有時不顯示。我用scale_linetype_manual()和guides()，但它不能產生預期的效果。但是

我創建的代碼，我刪除了顯示我嘗試製作圖例的代碼。

exemplo<-data.frame(Location = c("Tiburon Peninsula", "San Francisco","Santa Barbara area", "Santa Monica Mountains", "Marin County", 
          "Santa Cruz Mountains", "Monterey County", "San Diego County","California Coast"), 
       Area = c(5.9, 45, 110, 320, 529, 1386, 3324,4260, 24520), 
       Species = c(370L, 640L, 680L, 640L, 1060L, 1200L,1400L, 1450L, 2525L)) 
modelo<-lm(log(Species,10)~log(Area,10),data=exemplo) 

modelo_nls<-nls(Species~a*Area^z,start=list(a=1,z=0.25),data=exemplo) 
linha<-data.frame(x=log10(seq(1,25000,100)),y=log10(predict(modelo_nls,newdata=data.frame(Area=seq(1,25000,100))))) 
ggplot(data=exemplo,aes(x=log10(Area),y=log10(Species))) + geom_point() + 
geom_abline(intercept = modelo$coefficients[1], slope = modelo$coefficients[2],linetype="dotted") + 
geom_line(data=linha,aes(x=x,y=y),linetype="dashed")+   
xlab(label="Área(ha)") + ylab(label="Número de espécies") 

Answer 1

一種方法是將您的兩條預測線組合成一個數據框，並附加一列指示每行屬於哪個模型。

# Add model = 'A' to this data frame (I may have got A and B the wrong way round) 
    linha <- data.frame(x = log10(seq(1,25000,100)), 
         y = log10(predict(modelo_nls,newdata=data.frame(Area=seq(1,25000,100)))), 
         model = 'A') 

# Make data frame of line from modelo 
lin2 <- data.frame(x = log10(seq(1,25000,100)), 
        y = predict(modelo, newdata = list(Area = seq(1,25000,100))), 
        model = 'B') 

# Combine two models 
combinedLines <- rbind(linha, lin2) 

然後用模型繪製作爲審美

ggplot(data=exemplo,aes(x=log10(Area),y=log10(Species))) + geom_point() + 
geom_line(data=combinedLines, aes(x=x,y=y, linetype = model))+   
xlab(label="Área(ha)") + ylab(label="Número de espécies") 

Answer 2

這裏是你如何能做到這一點。

nlha <- data.frame(x=log10(seq(1,25000,100)),y=(predict(modelo,newdata=data.frame(Area=(seq(1,25000,100)))))) 
model_data <- cbind.data.frame(type=rep(c("A","B"),each=250),rbind(nlha,linha)) 
ggplot(data=exemplo,aes(x=log10(Area),y=log10(Species))) + geom_point() + geom_line(data=model_data,aes(x=x,y=y,linetype=type))+ xlab(label="Área(ha)") + ylab(label="Número de espécies") 

我希望它有幫助。