svm {e1071} 预测创建比预期更大的预测值数组

svm {e1071} predict creates larger array of predicted values than expected

我在 R 中使用支持向量机(SVM,包 e1071)来构建 class化模型和样本外预测 7 因子 class。

问题是,当使用预测函数时,我得到一个数组,比验证集中的行数大得多。请参阅下面的代码和结果。

对出了什么问题有什么建议吗?我是否误解了 SVM 包中的预测函数?

install.packages("e1071","caret")
library(e1071)
library(caret)

data <- data.frame(replicate(10,sample(0:6,1000,rep=TRUE)))

trainIndex <- createDataPartition(data[,1], p = 0.8,
                                  list = FALSE,
                                  times = 1)

trainset <- data[trainIndex,2:10]
validationset <- data[-trainIndex,2:10]

trainlabel <- data[trainIndex,1]
validationlabel <- data[-trainIndex,1]

svmModel <- svm(x = trainset, 
                y = trainlabel, 
                type = "C-classification", 
                kernel = "radial")

# Predict
svmPred <- predict(svmModel, x = validationset)

length(svmPred)
# 800, expected 200 since validationset has nrow = 200.

因为预测中没有x

尝试:

svmPred <- predict(svmModel, validationset)
length(svmPred)