[英]R caret package (rpart)
使用rpart库时出现以下错误
dt <- rpart(formula, method="class", data=full.df.allAttr.train);
Error in model.frame.default(formula = formula, data = full.df.allAttr.train, :
object is not a matrix
当我将full.df.allAttr.train转换为矩阵时
dt <- rpart(formula, method="class", data= as.matrix( full.df.allAttr.train));
Error in model.frame.default(formula = formula, data = as.matrix(full.df.allAttr.train), :
'data' must be a data.frame, not a matrix or an array
当我检查类时输入其数据框
class(full.df.allAttr.train)
[1] "data.frame"
谢谢您的投入,当我使用正确的列名创建公式并产生结果时,错误就消失了。
measurevar <- "SpeakerName"
formula_str <- paste(measurevar, paste(rowNames, collapse=" + "), sep=" ~ ")
formula <- as.formula(formula_str)
由于我的数据框具有row.names,而下面的文本是快照,它给出了一个不同的错误
Error in model.frame.default(formula = formula, data = full.df.train, :
variable lengths differ (found for 'character(0)')
抱歉,我将添加完整的源代码和数据集
library(tm)
library(rpart)
obamaCorpus <- Corpus(DirSource(directory = "D:/R/Chap 6/Speeches/obama" , encoding="UTF-8"))
romneyCorpus <- Corpus(DirSource(directory = "D:/R/Chap 6/Speeches/romney" , encoding="UTF-8"))
fullCorpus <- c(obamaCorpus,romneyCorpus)#1-22 (obama), 23-44(romney)
fullCorpus.cleansed <- tm_map(fullCorpus, removePunctuation)
fullCorpus.cleansed <- tm_map(fullCorpus.cleansed, stripWhitespace)
fullCorpus.cleansed <- tm_map(fullCorpus.cleansed, tolower)
fullCorpus.cleansed <- tm_map(fullCorpus.cleansed, removeWords, stopwords("english"))
fullCorpus.cleansed <- tm_map(fullCorpus.cleansed, PlainTextDocument)
#fullCorpus.cleansed <- tm_map(fullCorpus.cleansed, stemDocument)
full.dtm <- DocumentTermMatrix(fullCorpus.cleansed)
full.dtm.spars <- removeSparseTerms(full.dtm , 0.6)
full.matix <- data.matrix(full.dtm.spars)
full.df <- as.data.frame(full.matix)
full.df[,"SpeakerName"] <- "obama"
full.df$SpeakerName[21:44] <- "romney"
train.idx <- sample(nrow(full.df) , ceiling(nrow(full.df)* 0.6))
test.idx <- (1:nrow(full.df))[-train.idx]
rowNames <- colnames(full.df)
measurevar <- "SpeakerName"
formula_str <- paste(measurevar, paste(rowNames, collapse=" + "), sep=" ~ ")
formula <- as.formula(formula_str)
dt <- rpart(formula, method="class", data=full.df.train);
在最后一步失败
数据集在这里https://drive.google.com/folderview?id=0B1SogodTE-kJSHF6aFRmQURsV0U&usp=sharing
您忘记包含full.df.train
并且公式不正确。
这将起作用:
full.df.train <- full.df[train.idx, ]
dt <- rpart(SpeakerName ~ ., method = "class", data = full.df.train)
公式的问题是~
两侧都包含SpeakerName
。 如果要使用所有变量,请使用.
表达更加容易和紧凑。
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