Mercurial > hg > octave-nkf
annotate scripts/special-matrix/sylvester_matrix.m @ 8517:81d6ab3ac93c
Allow documentation tobe built for other formats than tex and info
| author | sh@sh-laptop |
|---|---|
| date | Wed, 14 Jan 2009 20:44:25 -0500 |
| parents | 83a8781b529d |
| children | eb63fbe60fab |
| rev | line source |
|---|---|
| 7017 | 1 ## Copyright (C) 1996, 1997, 1998, 1999, 2000, 2002, 2004, 2005, 2006, |
| 2 ## 2007 John W. Eaton | |
| 3140 | 3 ## |
| 4 ## This file is part of Octave. | |
| 5 ## | |
| 6 ## Octave is free software; you can redistribute it and/or modify it | |
| 7 ## under the terms of the GNU General Public License as published by | |
| 7016 | 8 ## the Free Software Foundation; either version 3 of the License, or (at |
| 9 ## your option) any later version. | |
| 3140 | 10 ## |
| 11 ## Octave is distributed in the hope that it will be useful, but | |
| 12 ## WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 14 ## General Public License for more details. | |
| 15 ## | |
| 16 ## You should have received a copy of the GNU General Public License | |
| 7016 | 17 ## along with Octave; see the file COPYING. If not, see |
| 18 ## <http://www.gnu.org/licenses/>. | |
| 3140 | 19 |
| 3369 | 20 ## -*- texinfo -*- |
| 21 ## @deftypefn {Function File} {} sylvester_matrix (@var{k}) | |
| 22 ## Return the Sylvester matrix of order | |
| 23 ## @iftex | |
| 24 ## @tex | |
| 25 ## $n = 2^k$. | |
| 26 ## @end tex | |
| 27 ## @end iftex | |
|
8517
81d6ab3ac93c
Allow documentation tobe built for other formats than tex and info
sh@sh-laptop
parents:
7411
diff
changeset
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28 ## @ifnottex |
| 3369 | 29 ## n = 2^k. |
|
8517
81d6ab3ac93c
Allow documentation tobe built for other formats than tex and info
sh@sh-laptop
parents:
7411
diff
changeset
|
30 ## @end ifnottex |
| 5642 | 31 ## @seealso{hankel, vander, hilb, invhilb, toeplitz} |
| 3369 | 32 ## @end deftypefn |
| 3140 | 33 |
| 34 ## Author: jwe | |
| 35 | |
| 36 function retval = sylvester_matrix (k) | |
| 37 | |
| 38 if (nargin != 1) | |
| 6046 | 39 print_usage (); |
| 3140 | 40 endif |
| 41 | |
| 4030 | 42 if (isscalar (k)) |
| 3140 | 43 if (k < 1) |
| 44 retval = 1; | |
| 45 else | |
| 46 tmp = sylvester_matrix (k-1); | |
| 47 retval = [tmp, tmp; tmp, -tmp]; | |
| 48 endif | |
| 49 else | |
| 50 error ("sylvester_matrix: expecting scalar argument"); | |
| 51 endif | |
| 52 | |
| 53 endfunction | |
| 7411 | 54 |
| 55 %!assert((sylvester_matrix (1) == [1, 1; 1, -1] | |
| 56 %! && (sylvester_matrix (2) | |
| 57 %! == [1, 1, 1, 1; 1, -1, 1, -1; 1, 1, -1, -1; 1, -1, -1, 1]))); | |
| 58 | |
| 59 %!error sylvester_matrix ([1, 2; 3, 4]); | |
| 60 | |
| 61 %!error sylvester_matrix (); | |
| 62 | |
| 63 %!error sylvester_matrix (1, 2); | |
| 64 |