pp=imread('C:\Users\zhangkun\Desktop\1.png')
p=rgb2gray(pp);
m=0;
len=size(p,1)
lie=size(p,2)
for i=1:len
    for j=1:lie
     if(p(i,j)==0)   
         m=m+1;
     end
    end
end
fugailv=m/(len*lie)%0.9346

L=1;                    % 节点布置区域
theta=0:pi/100:2*pi; 
n=100;                             % 节点个数
node_max=0.29;                  % 节点最大通信距离
X=unifrnd(0,L,1,n);           % 生成n个均匀随机数作为横坐标
B=sqrt(L^2-abs(X).^2);     % 计算每个x对应的y范围
Y=unifrnd(0,B,1,n);          % 对每个横坐标生成均匀随机数作为纵坐标
plot(X,Y,'.')
hold on
axis equal;
axis([0 1 0 1]); 
figure(1)
for i=1:n
   hold on
   x=node_max*cos(theta)+X(i);
   y=node_max*sin(theta)+Y(i);
   plot(x,y,'b-')
    %fill(x,y,'k');
end
figure(2)
axis equal;
axis([0 1 0 1]); 
for i=1:n
   hold on
   x=node_max*cos(theta)+X(i);
   y=node_max*sin(theta)+Y(i);
   %plot(x,y,'k-')
   fill(x,y,'k');
end

pp=imread('C:\Users\kkzhang\Desktop\1.png')
p=rgb2gray(pp);
m=0;
len=size(p,1)
lie=size(p,2)
for i=1:len
    for j=1:lie
     if(p(i,j)==0)   
         m=m+1;
     end
    end
end
fugailv=m/(len*lie)%0.9346