好的设计是:
先生产节点编号A_ind,在索引
% upper half for i=1:m/2-1 for j=1:n M=m/2-1; Begin=1; End= M*n; id=Begin-1+(j-1)*M +i; if(id+1<=End) A(id, id+1)=-1; end if(id-1>=Begin) A(id, id-1)=-1; end if(id+m<=End) A(id, id+M)=-1; end if(id-m>=Begin) A(id, id-M)=-1; end A(id, id )=4; k=k+1; end end for i=1:m/2-1 % -1 for j=1:n M2=m/2-1; % shift in id Begin2=End; % line 28 End2= End+M2*n; id=Begin2-1+(j-1)*M +i; if(id+1<=End2) A(id, id+1)=-1; end if(id-1>=Begin2) A(id, id-1)=-1; end if(id+M<=End2) A(id, id+M2)=-1; end if(id-M>=Begin2) A(id, id-M2)=-1; end A(id, id )=4; k=k+1; end end % interface % error for i=m for j=1:n M=m/2; id= (j-1)*M +i; if(1)%id+1<=mn/2) %A(id, id+1)=-1; index_j= id+ m*n/2- (i-1); A(id, index_j)=-1; end if(id-1>=1) A(id, id-1)=-1; end if(id+M<=mn/2) A(id, id+M)=-1; end if(id-M>=1) A(id, id-M)=-1; end A(id, id )=4; k=k+1; end end %}