R数值变量的NaiveBayes问题

Question

尽管NaiveBayes()帮助说明可以在第一个参数'x‘中传递数字，但我无法成功运行它。没有数值变量(转售)，它工作得很好。下面是脚本：

    library(readr)
    library(klaR)
    ### load dataset
    Dataset <- read_csv("D:/sampledata.csv")
    ### converting 'model' and 'type' to factor
    Dataset$model <- factor(Dataset$model)
    Dataset$type <- factor(Dataset$type)
    ### Executing NaiveBayes with numeric 'resale'
    NaiveBayesModel1 <- NaiveBayes(model~type+mylogical+resale,data=Dataset,na.action =na.omit)
    ### now removing resale. Following works as expected.
    NaiveBayesModel1 <- NaiveBayes(model~type+mylogical,data=Dataset,na.action =na.omit)

‘'model’和'type‘是因子，'mylogical’是逻辑变量，'resale‘是数值变量。因为我不能附加我的数据文件，所以我在这里粘贴了几行。复制这些行，并在驱动器上另存为sampledata.csv文件。修改上述脚本中的read_csv()以指向此csv文件。

"model","sales","resale","type","mylogical"
"Integra",16.919,16.36,"Automobile",TRUE
"TL",39.384,19.875,"Automobile",FALSE
"Camry",247.994,13.245,"Automobile",FALSE
"Avalon",63.849,18.14,"Automobile",TRUE
"Celica",33.269,15.445,"Automobile",TRUE
"Tacoma",84.087,9.575,"Truck",TRUE
"RAV4",25.106,13.325,"Truck",FALSE
"4Runner",68.411,19.425,"Truck",FALSE
"Land Cruiser",9.835,34.08,"Truck",TRUE
"Golf",9.761,11.425,"Automobile",FALSE
"Jetta",83.721,13.24,"Automobile",FALSE
"Passat",51.102,16.725,"Automobile",TRUE
"Cabrio",9.569,16.575,"Automobile",FALSE
"GTI",5.596,13.76,"Automobile",FALSE

如果我用"resale“运行NaiveBayes，我会得到以下错误。

Error in if (any(temp)) stop("Zero variances for at least one class in variables: ",  : 
  missing value where TRUE/FALSE needed

R help ( help(NaiveBayes) )告诉我可以使用数字。我不明白哪里出了问题。请帮帮忙。

致敬，SG

Answer 1

该错误是由model中每个结果的变量resale值的零方差引起的。最有可能的情况是，您的训练集包含model中每个不同值的单个训练记录。