Create a box-and-whisker plot
caret provides a variety of methods to use for comparing models. All of these methods are based on the resamples() function. My favorite is the box-and-whisker plot, which allows you to compare the distribution of predictive accuracy (in this case AUC) for the two models.
In general, you want the model with the higher median AUC, as well as a smaller range between min and max AUC.
You can make this plot using the bwplot() function, which makes a box and whisker plot of the model's out of sample scores. Box and whisker plots show the median of each distribution as a line and the interquartile range of each distribution as a box around the median line. You can pass the metric = "ROC" argument to the bwplot() function to show a plot of the model's out-of-sample ROC scores and choose the model with the highest median ROC.
If you do not specify a metric to plot, bwplot() will automatically plot 3 of them.
本练习是课程的一部分
Machine Learning with caret in R
练习说明
Pass the resamples object to the bwplot() function to make a box-and-whisker plot. Look at the resulting plot and note which model has the higher median ROC statistic. Be sure to specify which metric you want to plot.
交互式实操练习
通过完成这段示例代码来试试这个练习。
# Create bwplot