中文说明： 此代码被关乎 duda 模式分类书，第 2 章，计算机造句训练，问题 3。 这是一组数据的分类问题第一次与一个功能，和其他两个和三个维度特征空间与时间。决策规则，基于判别函数的正常浓度。
English Description：
this code is related to duda pattern classification book, chapter 2, computer excersices, problem 3. this is a classification problem for a data set, first with one feature and, and other times with two and three dimension feature space. the decision rule, is based on a discriminant function for the normal density.