【发布时间】:2017-02-16 20:51:07
【问题描述】:
我想为我的每个模型创建 boxplots 总计 MSE,以显示模型错误的可变性。为了生成显示错误分布的boxplot,对模型进行多次采样和拟合的最佳方法是什么?
对于每个模型,我将为所有数据(训练和测试)生成预测。然后,我将通过subsetting 相应地计算预测的火车MSE 和测试MSE。以下函数将同时计算两个MSE 值。
有没有更好的方法来重新采样和plot 每次重新采样时每个模型的 MSE?任何帮助将不胜感激。
calcMSE = function(model,modelLabel,dataSet,trainIdx,newX=NULL)
{
# The predict method for glmnet will need to be called differently from the
# other predict methods.
if ("glmnet" %in% class(model)) {
predVals = predict(model,newX,type="response")
} else {
predVals = predict(model,data)
}
MSE = list(
name = modelLabel,
train = mean((predVals[trainIdx] - data$y[trainIdx])^2),
test = mean((predVals[-trainIdx] - data$y[-trainIdx])^2)
)
return(MSE)
}
modelMSEs = data.frame(Model = rep(NA,8),Train.MSE = rep(NA,8),Test.MSE = rep(NA,8))
modelMSEs[1,] = calcMSE(modelA1,"A1",Data,trainIdx)
modelMSEs[2,] = calcMSE(modelA2,"A2",Data,trainIdx)
modelMSEs[3,] = calcMSE(modelB1,"B1",Data,trainIdx)
modelMSEs[4,] = calcMSE(modelB2,"B2",Data,trainIdx)
modelMSEs[5,] = calcMSE(modelC1,"C1",Data,trainIdx)
modelMSEs[6,] = calcMSE(modelC2,"C2",Data,trainIdx)
print(modelMSEs)
【问题讨论】: