小编use*_*537的帖子

如果因子变量是气候,有4个可能的值:热带,干旱,温带,雪和我rpart树中的节点标记为"气候:ab",分裂是什么？

我一直在敲打我的头rpart几天,现在(试图使分类树这个数据集,我有),我认为现在是时候在这一点上问一个生命线:-)我敢肯定它的东西愚蠢的我没有看到,但这是我一直在做的事情:

EuropeWater <- read.csv(file=paste("/Users/artessaniccola/Documents/",
                       "Magic Briefcase/CityTypology/Europe_water.csv",sep=""))
library(rpart)
attach(EuropeWater)
names(EuropeWater)
[1] "City"          "waterpercapita_m3" "water_class"       "population"       
[5] "GDPpercapita"  "area_km2"          "populationdensity" "climate"            
EuropeWater$water_class <- factor(EuropeWater$water_class, levels=1:3, 
                                  labels=c("Low", "Medium", "High"))
EuropeWater$climate <- factor(EuropeWater$climate, levels=2:4, 
                              labels=c("Arid", "Warm temperate", "Snow"))
EuropeWater_tree <- rpart(EuropeWater$water_class ~ 
               population+GDPpercapita + area_km2 + populationdensity + 
               EuropeWater$climate, 
               data=EuropeWater, method=class)   
Error in as.character(x) : 
          cannot coerce type 'builtin' to vector of type 'character'

而对于我的生活,我无法弄清楚错误是什么.