Mercurial > octave
view scripts/special-matrix/toeplitz.m @ 4:b4df021f796c
[project @ 1993-08-08 01:26:08 by jwe]
Initial revision
author | jwe |
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date | Sun, 08 Aug 1993 01:26:08 +0000 |
parents | |
children | 16a24e76d6e0 |
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function retval = toeplitz (c, r) # usage: toeplitz (c, r) # # Return the Toeplitz matrix constructed given the first column # c, and (optionally) the first row r. # # If the second argument is omitted, the first row is taken to be the # same as the first column. If the first element of c is not the same # as the first element of r, the first element of c is used. # # See also: hankel, vander, hadamard, hilb, invhib if (nargin == 1) r = c; elseif (nargin != 2) error ("usage: toeplitz (c, r)"); endif [c_nr, c_nc] = size (c); [r_nr, r_nc] = size (r); if ((c_nr != 1 && c_nc != 1) || (r_nr != 1 && r_nc != 1)) error ("toeplitz: expecting vector arguments") endif if (c_nc != 1) c = c'; endif if (r_nr != 1) r = r'; endif if (r (1) != c (1)) disp ("Column wins diagonal conflict"); endif # This should probably be done with the colon operator... nc = length (r); nr = length (c); retval = zeros (nr, nc); for i = 1:min (nc, nr) retval (i:nr, i) = c (1:nr-i+1); endfor for i = 1:min (nr, nc-1) retval (i, i+1:nc) = r (2:nc-i+1); endfor endfunction