中文说明：针对二维三类问题 ，画出三类的类条件概率曲面，及投影到二维空间的同概率轨迹及决策曲线。matlab仿真
English Description：
For two-dimensional three-class problems, draw the three types of surfaces class conditional probability, and projected onto a two-dimensional space of curve trajectory with probability and decision making. MATLAB simulation