[R] weird predict function error when I use naive bayes

[Uwe Ligges]

On 04.05.2012 13:54, kiinalist wrote:
> Hi,
>
> I tried to use naivebayes in package 'e1071'.
> when I use following parameter, only one predictor, there is an error.
>
>> m<- naiveBayes(iris[,1], iris[,5])
>> table(predict(m, iris[,1]), iris[,5])
> Error in log(sapply(attribs, function(v) { :
> Non-numeric argument to mathematical function

Either use the more convninient formula notation:

m <- naiveBayes(Species ~ Sepal.Length, data = iris)
table(predict(m, iris), iris$Species)


or provide data.frames rather than vectors, hence:


m <- naiveBayes(iris[,1,drop=FALSE], iris[,5])
table(predict(m, iris[,1,drop=FALSE]), iris[,5])

Uwe Ligges



>
> However, when I use two predictors, there is not error any more.
>
>> m<- naiveBayes(iris[,1:2], iris[,5])
>> table(predict(m, iris[,1:2]), iris[,5])
>
> setosa versicolor virginica
> setosa 49 0 0
> versicolor 1 37 19
> virginica 0 13 31
>
> Do you know what is the problem?
>
> Br,
> Luffy
>
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