ash.m

一些常被用于教学或者参考的概率论的实例的源代码

%ash.m/created by PJNahin for "Duelling Idiots"(11/15/98)
%This m-file is chess.m modified to implement Ash's special
%values of p=q=1/3.
%
%
N=input('Number of games in match? ')
q=1/3;
ANSWER=zeros(3,round(100*(1-q)));
p=1/3;
   g=(1-p-q)*p;
   RZ=zeros(1,N);
   C=zeros(N);
   for k=1:N
      C(k,k)=p^k;
   end
   for n=1:N
   if 2*round(n/2)==n
      for d=0:2:n
         top=(n+d)/2;
         bottom=(n-d)/2;
         I=binomial(n,bottom)*binomial(top,bottom);
         I=I*(g^bottom)*(q^d);
         RZ(n)=RZ(n)+I;
      end
   else
      for d=1:2:n
         top=(n+d)/2;
         bottom=(n-d)/2;
         I=binomial(n,bottom)*binomial(top,bottom);
         I=I*(g^bottom)*(q^d);
         RZ(n)=RZ(n)+I;
      end
   end
   end
     g=1-p-q;
   for c=2:N
      k=1;
      n=c;
      while n<=N
         C(k,n)=C(k,n-1)*q+C(k+1,n-1)*g;
         if k==1
            C(k,n)=C(k,n)+RZ(n-1)*p;
         else
            C(k,n)=C(k,n)+C(k-1,n-1)*p;
         end
         k=k+1;
         n=n+1;
      end
   end
   SUM=0;
   for k=1:N
      SUM=SUM+C(k,N);
   end
   RZ(N)