R 使用ggplot2转换图表中线条的颜色

我正在做一些与插入符号包相关的预测。您可以在下面看到此预测的输出

data_for.cm_rpart <- data.table(Data = c(final_predictions.rpart$Customs_duties,final_predictions.rpart$Predictions),                      
                                              Date = c( rep(final_predictions.rpart$Date )),
                                              Type = c(#rep("Train data", nrow(data_train)),
                                                rep("Test data", nrow(final_predictions.rpart)),
                                                rep("Forecast", nrow(final_predictions.rpart))))
              
              ggplot(data_for.cm_rpart, aes(Date, Data, color = Type), palette = c("#0073C2FF", "#FC4E07")) +
                geom_line(size = 0.9, alpha = 0.75)

---

data\u for.cm\u rpart也许您应该在
aes
中设置alpha，然后使用
scale\u alpha\u手册
对其进行更改，以便两行具有不同的透明度

# example data
data_for.cm_rpart = data.frame(Date = 2017:2020, 
                               Data = c(1:4, 3:4, 3:4), 
                               Type = c(rep('forecast',4), 
                                        rep('test data', 4)))

# plot
ggplot(data_for.cm_rpart, aes(Date, Data, color = Type, alpha = Type), 
       palette = c("#0073C2FF", "#FC4E07")) +
  geom_line(size = 0.9)+
  scale_alpha_manual(values = c(1, 0.5))