www.pudn.com > nsct_toolbox.rar > resampz.m, change:2003-04-10,size:1981b

```function y = resampz(x, type, shift)
% RESAMPZ   Resampling of matrix
%
%       y = resampz(x, type, [shift])
%
% Input:
%       x:      input matrix
%       type:   one of {1, 2, 3, 4} (see note)
%       shift:  [optional] amount of shift (default is 1)
%
% Output:
%       y:      resampled matrix
%
% Note:
%	The resampling matrices are:
%		R1 = [1, 1;  0, 1];
%		R2 = [1, -1; 0, 1];
%		R3 = [1, 0;  1, 1];
%		R4 = [1, 0; -1, 1];
%
%	This resampling program does NOT involve periodicity, thus it
%	zero-pad and extend the matrix
%

if ~exist('shift', 'var')
shift = 1;
end

sx = size(x);

switch type
case {1, 2}
y = zeros(sx(1) + abs(shift * (sx(2) - 1)), sx(2));

if type == 1
shift1 = [0:(sx(2)-1)] * (-shift);
else
shift1 = [0:(sx(2)-1)] * shift;
end

% Adjust to non-negative shift if needed
if (shift1(end) < 0)
shift1 = shift1 - shift1(end);
end

for n = 1:sx(2)
y(shift1(n)+(1:sx(1)), n) = x(:, n);
end

% Finally, delete zero rows if needed
start = 1;
finish = size(y, 1);

while norm(y(start, :)) == 0,
start = start + 1;
end

while norm(y(finish, :)) == 0,
finish = finish - 1;
end

y = y(start:finish, :);

case {3, 4}
y = zeros(sx(1), sx(2) + abs(shift * (sx(1) - 1)));

if type == 3
shift2 = [0:(sx(1)-1)] * (-shift);
else
shift2 = [0:(sx(1)-1)] * shift;
end

% Adjust to non-negative shift if needed
if (shift2(end) < 0)
shift2 = shift2 - shift2(end);
end

for m = 1:sx(1)
y(m, shift2(m)+(1:sx(2))) = x(m, :);
end

% Finally, delete zero columns if needed
start = 1;
finish = size(y, 2);

while norm(y(:, start)) == 0,
start = start + 1;
end

while norm(y(:, finish)) == 0,
finish = finish - 1;
end

y = y(:, start:finish);

otherwise
error('The second input (type) must be one of {1, 2, 3, 4}');
end```