weka.core.UnsupportedAttributeTypeException：weka.classifiers.trees.j48.C45PruneableClassifierTree：文字列を扱うことができない属性

Question

I次のコードを持っている：J48から私のためにベイジアンネットワーク図をプロットすることになっている

#load required library 
library(data.tree) 
library(entropy) 
library(RWeka) 
library(partykit) 
library(FSelector) 
library(e1071) 
library(caret) 
library(RWekajars) 


#Load dataset 
rest_contries <- fromJSON("https://restcountries.eu/rest/v1/all") 
View(rest_contries) 
class(rest_contries) 
dim(rest_contries) 
cleaned_rest_countries <- rest_contries[,c(1,2,5,6)] 
View(cleaned_rest_countries) 
#================ J48 Algorithm ================================================= 
m <- J48(region~., data = cleaned_rest_countries) 
plot(m) 

アルゴリズム。

> m <- J48(region~., data = cleaned_rest_countries) 
Error in .jcall(o, "Ljava/lang/Class;", "getClass") : 
    weka.core.UnsupportedAttributeTypeException: weka.classifiers.trees.j48.C45PruneableClassifierTree: Cannot handle string attributes! 

問題の解決を支援してください：私は次のエラーを取得する方法は、これまで 。 CSVからデータを読み込むとうまくいきますが、jsonから文字列属性エラーが発生します。

Answer 1

文字変数を要素に変換する必要があると思われます。

> cleaned_rest_countries <- lapply(cleaned_rest_countries, as.factor) 
> m <- J48(region~., data = cleaned_rest_countries) 
> m 
J48 pruned tree 
------------------ 

subregion = : (3.0) 
subregion = Australia and New Zealand: Oceania (5.0) 
subregion = Caribbean: Americas (27.0) 
subregion = Central America: Americas (8.0) 
subregion = Central Asia: Asia (5.0) 
subregion = Eastern Africa: Africa (20.0) 
subregion = Eastern Asia: Asia (8.0) 
subregion = Eastern Europe: Europe (11.0) 
subregion = Melanesia: Oceania (5.0) 
subregion = Micronesia: Oceania (7.0) 
subregion = Middle Africa: Africa (10.0) 
subregion = Northern Africa: Africa (7.0) 
subregion = Northern America: Americas (6.0) 
subregion = Northern Europe: Europe (16.0) 
subregion = Polynesia: Oceania (10.0) 
subregion = South-Eastern Asia: Asia (11.0) 
subregion = South America: Americas (15.0) 
subregion = Southern Africa: Africa (5.0) 
subregion = Southern Asia: Asia (9.0) 
subregion = Southern Europe: Europe (16.0) 
subregion = Western Africa: Africa (17.0) 
subregion = Western Asia: Asia (17.0) 
subregion = Western Europe: Europe (9.0) 

Number of Leaves :  23 

Size of the tree : 24 

の