Zigzag逆掃描

Zigzag逆掃描代碼 MATLAB版

即將一個1 * k 長度的向量，逆掃描爲 M * N 的矩陣（如果 k < M * N，則在 M * N 的矩陣中用 0 補齊；若 k > M * N，則向量會被截斷）。

代碼如下，僅供參考。

function mtr = izigzagScan(vec, m, n)
% izigzagScan(vec, m, n) Inverse zigzag scan.
% mtr = izigzagScan(vec, m, n) inverse zigzag scan of vec, and the target
% matrix is m-by-n. The input parameter vec is an 1-by-k vector. If the
% length of vector is smaller than the size of mtr (i.e. k < m*n), then, the
% pargram will use 0 to fill the matrix. If k > m*n, the vector will be truncated.
%
% version: v1.0
% author: tianlan
% time: Dec 16, 2016

% CHECK INPUT ARGUMENTS
if nargin < 3
    error('Not enough input arguments!');
elseif nargin > 3
    error('Too many input arguments!');
end
% Get length of vector.
[mv,nv,tv] = size(vec);
if tv ~= 1 || mv ~=1
    error('The input vector needs to be 1-by-k vector!');
end
if nv < m*n % if nv < m*n, then, use 0 to fill the matrix.
    vec = [vec, zeros(1,m*n-nv)];
end
% REVERSE SCAN A VECTOR BY USING ZIGZAG ORDER.
mtr = zeros(m,n);
% zigzag scan.
x = 1;
y = 1;
vecNum = 0;
vecNum = vecNum + 1;
mtr(x,y) = vec(1,vecNum);
while 1
    % arrive right-up border, needs to change direction.
    if (y+1) <= n && x == 1 % towards right one step.
        y = y + 1;
    elseif (y+1) > n && (x+1) <= m % towards down one step.
        x = x + 1;
    else
        break;
    end
    vecNum = vecNum + 1;
    mtr(x,y) = vec(1,vecNum) ;
    % judge the scan process is arrived the right-down corner (i.e. mtr(m,n)) or not.
    if x == m && y == n 
        break;
    end
    % scan the matrix towards with left-down direction.
    while (y-1) >= 1 && (x+1) <= m
            y = y - 1;
            x = x + 1;
            vecNum = vecNum + 1;
            mtr(x,y) = vec(1,vecNum);
    end
    % arrive the left-down border, needs to change direction.
    if (x+1) <= m && y == 1% towards down one step.
        x = x + 1;
    elseif (y+1) <= n && x == m % towards right one step.
        y = y + 1;
    else
        break;
    end
    vecNum = vecNum + 1;
    mtr(x,y) = vec(1,vecNum);
    % judge the scan process is arrived the right-down corner (i.e. mtr(m,n)) or not.
    if x == m && y == n 
        break;
    end
    % scan the matrix towards with right-up direction.
    while (x-1) >= 1 && (y+1) <= n
        x = x - 1;
        y = y + 1;
        vecNum = vecNum + 1;
        mtr(x,y) = vec(1,vecNum);
    end
end