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| -rw-r--r-- | macros/ifftshift1.sci | 105 |
1 files changed, 82 insertions, 23 deletions
diff --git a/macros/ifftshift1.sci b/macros/ifftshift1.sci index 7426130..c81a285 100644 --- a/macros/ifftshift1.sci +++ b/macros/ifftshift1.sci @@ -1,24 +1,83 @@ -function y= ifftshift1(X,DIM) +function y = ifftshift1(x, dim) //Undo the action of the 'fftshift1' function. -//Calling Sequence -// ifftshift1 (X) -// ifftshift1 (X, DIM) -//Parameters -//X:It is a vector of N elements corresponding to time samples -//DIM: The optional DIM argument can be used to limit the dimension along which the permutation occurs -//Description -//This is an Octave function. -//Undo the action of the 'fftshift1' function. -// -//For even length X, 'fftshift1' is its own inverse, but odd lengths differ slightly. - rhs= argn(2); - if(rhs <1 | rhs >2) - error('Wrong number of Input arguments'); - end - select(rhs) - case 1 then - y=callOctave("ifftshift",X); - case 2 then - y=callOctave("ifftshift",X,DIM); - end -endfunction
\ No newline at end of file +//Calling Sequence: +// ifftshift1(x) +// ifftshift1(x, dim) +//Parameters: +//x- It is a vector of N elements corresponding to time samples +//dim- The optional DIM argument can be used to limit the dimension along which the permutation occurs +//Description: +//Undoes the action of the 'fftshift1' function. For 'x' of even length 'fftshift1' is its own inverse, but odd lengths differ slightly. +//Examples: +//x = [1, 2, 3, 4]; +//ifftshift1(fftshift1(x)); +//ans = +//[1, 2, 3, 4]; + + funcprot(0); + rhs = argn(2); + if (rhs < 1 | rhs > 2) then + error ("ifftshift1: wrong number of arguments"); + end + + if (~or(type(x) == [1 5 8 10 4 6])) + error ("ifftshitft1: arg1 (x) must be a vector or matrix"); + end + + if (rhs == 1) then + dim = 1:max(size(size(x))); + else + if (~(isscalar(dim) & dim > 0 & dim == fix(dim))) then + error ("ifftshift1: arg2 (dim) must be a positive integer"); + end + end + + for d = dim + sz = size(x); + sz2 = floor(sz(d) / 2); + dim_idx = [sz2+1:sz(d), 1:sz2]; + if (d == 1) then + x = x(dim_idx, :); + elseif ( d == max(size(size(x))) ) then + x = x(:, dim_idx); + else + idx = repmat({':'}, 1, max(size(size(x)))); + idx(d) = {dim_idx}; + x = x(idx{:}); + end + end + y = x; + +endfunction + +//input validation: +//assert_checkerror("ifftshift1()", "ifftshift1: wrong number of arguments"); +//assert_checkerror("ifftshift1(1, 2, 3)", "Wrong number of input arguments."); +//assert_checkerror("ifftshift1(0:2, -1)", "ifftshift1: arg2 (dim) must be a positive integer"); +//assert_checkerror("ifftshift1(0:2, 0:3)", "ifftshift1: arg2 (dim) must be a positive integer"); + +//test mx1 input: +//x = [0:7]; +//y = ifftshift1(x); +//assert_checkequal(y, [4 5 6 7 0 1 2 3]); +//assert_checkequal(ifftshift1(y), x); + +//test 1xm input: +//x = [0:6]'; +//y = ifftshift1(x); +//assert_checkequal(y, [3;4;5;6;0;1;2]); +//assert_checkequal(ifftshift1(y), [6;0;1;2;3;4;5]); + +//test mxn input: +//x = [0:3]; +//x = [x;2*x;3*x+1;4*x+1]; +//y = ifftshift1(x); +//assert_checkequal(y, [[7 10 1 4];[9 13 1 5];[2 3 0 1];[4 6 0 2]]); +//assert_checkequal(ifftshift1(y), x); + +//test dim is provided: +//x = [0:3]; +//x = [x;2*x;3*x+1;4*x+1]; +//y = ifftshift1(x, 2); +//assert_checkequal(y, [[2 3 0 1];[4 6 0 2];[7 10 1 4];[9 13 1 5]]); +//assert_checkequal(ifftshift1(y, 2), x); |