Mercurial > hg > octave-lyh
annotate scripts/polynomial/polyderiv.m @ 11469:c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
| author | Rik <octave@nomad.inbox5.com> |
|---|---|
| date | Sun, 09 Jan 2011 12:41:21 -0800 |
| parents | a8ce6bdecce5 |
| children | fd0a3ac60b0e |
| rev | line source |
|---|---|
| 7017 | 1 ## Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2002, 2004, |
| 8920 | 2 ## 2005, 2006, 2007, 2008 John W. Eaton |
| 2313 | 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. | |
| 2313 | 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/>. | |
| 904 | 19 |
| 3368 | 20 ## -*- texinfo -*- |
|
11469
c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
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21 ## @deftypefn {Function File} {} polyderiv (@var{p}) |
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c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
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22 ## @deftypefnx {Function File} {[@var{k}] =} polyderiv (@var{a}, @var{b}) |
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c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
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23 ## @deftypefnx {Function File} {[@var{q}, @var{d}] =} polyderiv (@var{b}, @var{a}) |
| 3368 | 24 ## Return the coefficients of the derivative of the polynomial whose |
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11469
c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
|
25 ## coefficients are given by the vector @var{p}. If a pair of polynomials |
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c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
|
26 ## is given, return the derivative of the product @math{@var{a}*@var{b}}. |
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c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
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27 ## If two inputs and two outputs are given, return the derivative of the |
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c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
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28 ## polynomial quotient @math{@var{b}/@var{a}}. The quotient numerator is |
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c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
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29 ## in @var{q} and the denominator in @var{d}. |
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10224
f6e0404421f4
point to polyint in @seealso, not polyinteg
John W. Eaton <jwe@octave.org>
parents:
8920
diff
changeset
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30 ## @seealso{poly, polyint, polyreduce, roots, conv, deconv, residue, |
| 5642 | 31 ## filter, polygcd, polyval, polyvalm} |
| 3368 | 32 ## @end deftypefn |
| 1025 | 33 |
| 3202 | 34 ## Author: Tony Richardson <arichard@stark.cc.oh.us> |
| 2312 | 35 ## Created: June 1994 |
| 36 ## Adapted-By: jwe | |
| 561 | 37 |
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11469
c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
|
38 function [q, d] = polyderiv (p, a) |
| 5216 | 39 |
| 5217 | 40 if (nargin == 1 || nargin == 2) |
| 41 if (! isvector (p)) | |
| 5216 | 42 error ("polyderiv: argument must be a vector"); |
| 43 endif | |
| 5217 | 44 if (nargin == 2) |
| 45 if (! isvector (a)) | |
| 10549 | 46 error ("polyderiv: argument must be a vector"); |
| 5217 | 47 endif |
| 48 if (nargout == 1) | |
| 10549 | 49 ## derivative of p*a returns a single polynomial |
| 50 q = polyderiv (conv (p, a)); | |
| 5217 | 51 else |
| 10549 | 52 ## derivative of p/a returns numerator and denominator |
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11469
c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
|
53 d = conv (a, a); |
| 10549 | 54 if (numel (p) == 1) |
| 55 q = -p * polyderiv (a); | |
| 56 elseif (numel (a) == 1) | |
| 57 q = a * polyderiv (p); | |
| 58 else | |
| 59 q = conv (polyderiv (p), a) - conv (p, polyderiv (a)); | |
| 60 q = polyreduce (q); | |
| 61 endif | |
| 5217 | 62 |
| 10549 | 63 ## remove common factors from numerator and denominator |
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11469
c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
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64 x = polygcd (q, d); |
| 10549 | 65 if (length(x) != 1) |
| 66 q = deconv (q, x); | |
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11469
c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
|
67 d = deconv (d, x); |
| 10549 | 68 endif |
| 5217 | 69 |
| 10549 | 70 ## move all the gain into the numerator |
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11469
c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
|
71 q = q/d(1); |
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c776f063fefe
Overhaul m-script files to use common variable name between code and documentation.
Rik <octave@nomad.inbox5.com>
parents:
10687
diff
changeset
|
72 d = d/d(1); |
| 5217 | 73 endif |
| 5216 | 74 else |
| 5217 | 75 lp = numel (p); |
| 76 if (lp == 1) | |
| 10549 | 77 q = 0; |
| 78 return; | |
| 5217 | 79 elseif (lp == 0) |
| 10549 | 80 q = []; |
| 81 return; | |
| 5216 | 82 endif |
| 561 | 83 |
| 5217 | 84 ## Force P to be a row vector. |
| 85 p = p(:).'; | |
| 5135 | 86 |
| 5217 | 87 q = p(1:(lp-1)) .* [(lp-1):-1:1]; |
| 5216 | 88 endif |
| 89 else | |
| 6046 | 90 print_usage (); |
| 5216 | 91 endif |
| 561 | 92 |
| 7411 | 93 endfunction |
| 5217 | 94 |
| 7411 | 95 %!assert(all (all (polyderiv ([1, 2, 3]) == [2, 2]))); |
| 96 | |
| 97 %!assert(polyderiv (13) == 0); | |
| 98 | |
| 99 %!error polyderiv ([]); | |
| 100 | |
| 101 %!error polyderiv ([1, 2; 3, 4]); | |
| 102 |