The y-axis should be the average error rates over all folds.
That's what people call the cross validation error.
TA
※ 引述《Yyh (我爱批踢踢)》之铭言：
: The curve drawed with k(knn) as x-axis and C.V. as y-axis, remember that?
: I can not figure out the meaning of that curve.
: (Is y-axis C.V. the number of folds?)
: I think the error rate can be put on y-axis, and
: different curves with different folds could be plot on the graph.
: Thanks for any reply.