机器学习二：感知器算法实现

本文主要是介绍机器学习二：感知器算法实现，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

本次也是用processing3.0+写的，其官方网站https://processing.org/，建议直接看reference的例子进行学习。

感知器算法用的是我们老师给的ppt，实现的是二维的感知器，为了方便看，实际上多维的也是一样的：

运行效果是：

为了试验方便，我这是用了点击取点，键盘按一下t，大小写均可，下一个点的就是正例，按一下f，大小写均可，下一个点就是负例。

按s是开始进行学习度为1的迭代。结束会直接出直线，按2会出学习率为2的直线，迭代次数会打在程序底下，值是2.

代码仅供参考，请勿抄袭。转载请注明出处。

//blog:http://www.cnblogs.com/SweetBeens/p/8176764.html
class Point{float x, y;int k;Point(float x1,float y1){x = x1; y = y1;}
}
int num = 500;
int len = 0;
float h=1;
float r=0;
Point [] points = new Point[num];
int irit = 1000;
float w1 = 0, w2 = 0, b = 0;
//false=-1,true=1
boolean type = true;
//if one point wrong,then ,you need another irretate
boolean flag = true;
//one irretate
void rewrite(){for(int i = 0; i < len; i++){//if points[i] wrong sidefloat result=points[i].k*(points[i].x*w1+points[i].y*w2+b);if(result<=0){w1 = w1+h*points[i].k*points[i].x;w2 = w2+h*points[i].k*points[i].y;b = b + h * points[i].k*r*r ;print(b," ");//w1=w1/w2;// w2=1;//b=b/w2;flag=true;}}}
//calculate R,check out in ppt 
void R(){float max=0;for(int i=0;i<len;i++){if(abs(points[i].x)>max)max=abs(points[i].x);if(abs(points[i].y)>max)max=abs(points[i].y);}r=max;println("max ",max);
}
void mousePressed(){Point p = new Point(mouseX,mouseY);if(type){p.k = 1;fill(255);}else{p.k = -1;fill(0);}rect(mouseX,mouseY,5,5);points[len] = p;len++;
}
void keyPressed(){int i=0;float y1=0,y2=0;if(key == 'T' || key == 't')type = true;else if(key == 'F' || key == 'f')type = false;else if(key == 's' || key == 'S'){R();while(i<irit&&flag==true){i++;flag=false;rewrite();//  println("w",w1," ",w2,"b",b);y1 = -b/w2;y2 = (-b-w1*width) / w2;//line(0,10,width,480);
   }println(y1," ",y2);println("w1,w2,b "+w1,w2,b);line(0,y1,width,y2);}else if(key == '2'){h = 0.2;w1 = 0;w2 = 0;b = 0;flag=true;i=0;while(i<irit&&flag==true){i++;flag=false;rewrite();//  println("w",w1," ",w2,"b",b);y1 = -b/w2;y2 = (-b-w1*width) / w2;//line(0,10,width,480);
   }println(y1," ",y2);println("w1,w2,b "+w1,w2,b);line(0,y1,width,y2);}println("i ",i);
}
void setup(){size(500,500);background(255);
}
void draw(){
}