Question

我在尝试使用插入符包训练数据集时遇到错误。错误如下...... Error in train.default(x, y, weights = w, ...) : Stopping。我还有warnings()，所有这些都是相同的，因为我正在使用以下代码为tuneGrid创建一个对象... grid <- expand.grid(cp = seq(0, 0.05, 0.005))。此代码创建了一个data.frame，其中包含11行，对应于我所拥有的11个警告。以下是警告... In eval(expr, envir, enclos) : model fit failed for Fold01: cp=0 Error in [.data.frame (m, labs) : undefined columns selected。看起来cp没有任何东西。我可以去我的环境看到网格对象和所有11行。我有搜索stackoverflow，我发现了类似的问题，但由于这些函数有很多方法来调整它们，我没有找到解决我的问题的问题。这是我的代码......

require(rpart)
require(rattle)
require(rpart.plot)
require(caret)


setwd('~/Documents/Lipscomb/predictive_analytics/class4/')
data <- read.csv(file = 'data.csv',
                 head = FALSE)

data <- subset(data, select = -V1)

colnames(data) <-  c('diagnostic', 'm.radius', 'm.texture', 'm. perimeter', 'm.area', 'm.smoothness', 'm.compactness', 'm.concavity', 'm.concave.points', 'm.symmetry', 'm.fractal.dimension',
                     'se.radius', 'se.texture', 'se. perimeter', 'se.area', 'se.smoothness', 'se.copactness', 'se.concavity', 'se.concave.points', 'se.symmetry', 'se.fractal.dimension',
                     'w.radius', 'w.texture', 'w. perimeter', 'w.area', 'w.smoothness', 'w.copactness', 'w.concavity', 'w.concave.points', 'w.symmetry', 'w.fractal.dimension')

str(data)

set.seed(7)
sample.train <- sample(1:nrow(data), nrow(data) * .8)
sample.test <- setdiff(1:nrow(data), sample.train)


data.train <- data[sample.train, ]
data.test <- subset(data[sample.test, ], select = -diagnostic)

rpart.tree <- rpart(diagnostic ~ ., data = data.train)
out <- predict(rpart.tree, data.test, type = 'class')
table(out, data[sample.test, ]$diagnostic)

fancyRpartPlot(rpart.tree)

temp <- rpart.control(xval = 10, minbucket = 2, minsplit = 4, cp = 0)
dfit <- rpart(diagnostic ~ ., data = data.train, control = temp)
fancyRpartPlot(dfit)

fit.control <- trainControl(method = 'cv', number = 10)
grid <- expand.grid(cp = seq(0, 0.05, 0.005))
trained.tree <- train(diagnostic ~ ., method = 'rpart', data = data.train, 
                      metric = 'Accuracy', maximize = TRUE,
                      trControl = fit.control, tuneGrid = grid)

Answer 1

我找到了解决这个问题的方法。我改变了命名colnames的方式。出于某种原因，命名colnames的原始代码导致使用train函数的错误。这段代码解决了这个问题。

colnames(data) <-  c('diagnostic', 'radius', 'texture', 'perimeter', 'area', 'smoothness', 'compactness', 'concavity', 'concavePoints', 'symmetry', 'fractalDimension',
                     'SeRadius', 'SeTexture', 'SePerimeter', 'SeArea', 'SeSmoothness', 'SeCopactness', 'SeConcavity', 'SeConcavePoints', 'SeSymmetry', 'SeFractalDimension',
                     'Wradius', 'Wtexture', 'Wperimeter', 'Warea', 'Wsmoothness', 'Wcopactness', 'Wconcavity', 'WconcavePoints', 'Wsymmetry', 'WfractalDimension')

使用插入符方法rpart R进行错误训练

1 个答案: