vector2zigzagmtx.m

有关向量2Z变换的matlab源码

function out=Vector2ZigzagMtx(in)
 
% out=Vector2ZigzagMtx(in)
% Convert every element in vector to square matrix with zigzag order
%
% e.g.  1 2 3 4 5 6 7 8 9
% ==>
%        1 2 6 
%        3 5 7 
%        4 8 9
%
% Author : Guan-Ming Su
% Date : 10/08/00

Dmtx=sqrt(length(in));
out=zeros(Dmtx,Dmtx);
TurnFlg=0;   % 0 for down trun, 1 for up trun
index=2;
out(1,1)=in(1);

for w=3:Dmtx+1
  switch TurnFlg
    case 0,
      for i=1:w-1
        j=w-i;
        out(i,j)=in(index);
        index=index+1;        
      end
      TurnFlg=1;
    case 1,
      for i=w-1:-1:1
        j=w-i;
        out(i,j)=in(index);
        index=index+1;
      end
      TurnFlg=0;        
   end
end

if mod(Dmtx,2)==0
   TurnFlg=1;
else
   TurnFlg=0;
end      

for w=Dmtx+2:2*Dmtx
  switch TurnFlg
    case 0,
      for i=w-Dmtx:Dmtx
        j=w-i;
        out(i,j)=in(index);
        index=index+1;        
      end
      TurnFlg=1;
    case 1,
      for i=Dmtx:-1:w-Dmtx
        j=w-i;
        out(i,j)=in(index);
        index=index+1;
      end
      TurnFlg=0;        
   end
end