Mercurial > hg > octave-nkf
annotate scripts/polynomial/ppval.m @ 12118:973f585cfdf2 release-3-2-x
include PTHREAD_CFLAGS in LINK_DEPS for liboctave
| author | Jaroslav Hajek <highegg@gmail.com> |
|---|---|
| date | Fri, 22 Jan 2010 10:21:33 +0100 |
| parents | eb63fbe60fab |
| children | 31900e17b5f5 |
| rev | line source |
|---|---|
| 8920 | 1 ## Copyright (C) 2000, 2006, 2007, 2008 Paul Kienzle |
| 5824 | 2 ## |
| 3 ## This file is part of Octave. | |
| 4 ## | |
| 5 ## Octave is free software; you can redistribute it and/or modify it | |
| 6 ## under the terms of the GNU General Public License as published by | |
| 7016 | 7 ## the Free Software Foundation; either version 3 of the License, or (at |
| 8 ## your option) any later version. | |
| 5824 | 9 ## |
| 10 ## Octave is distributed in the hope that it will be useful, but | |
| 11 ## WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 ## General Public License for more details. | |
| 14 ## | |
| 15 ## You should have received a copy of the GNU General Public License | |
| 7016 | 16 ## along with Octave; see the file COPYING. If not, see |
| 17 ## <http://www.gnu.org/licenses/>. | |
| 5824 | 18 |
| 19 ## -*- texinfo -*- | |
| 5831 | 20 ## @deftypefn {Function File} {@var{yi} =} ppval (@var{pp}, @var{xi}) |
| 5824 | 21 ## Evaluate piece-wise polynomial @var{pp} at the points @var{xi}. |
| 22 ## If @code{@var{pp}.d} is a scalar greater than 1, or an array, | |
| 23 ## then the returned value @var{yi} will be an array that is | |
| 24 ## @code{d1, d1, @dots{}, dk, length (@var{xi})]}. | |
| 25 ## @seealso{mkpp, unmkpp, spline} | |
| 26 ## @end deftypefn | |
| 27 | |
| 28 function yi = ppval (pp, xi) | |
| 29 | |
| 30 if (nargin != 2) | |
| 6046 | 31 print_usage (); |
| 5824 | 32 endif |
| 33 if (! isstruct (pp)) | |
| 34 error ("ppval: expects a pp structure"); | |
| 35 endif | |
| 36 if (isempty (xi)) | |
| 37 yi = []; | |
| 38 else | |
| 39 transposed = (columns (xi) == 1); | |
| 40 xi = xi(:); | |
| 41 xn = length (xi); | |
|
7671
4fbaba9abec1
implement compiled binary lookup
Jaroslav Hajek <highegg@gmail.com>
parents:
7017
diff
changeset
|
42 idx = lookup (pp.x, xi, "lr"); |
| 6014 | 43 dx = (xi - pp.x(idx)).'; |
| 5824 | 44 dx = reshape (dx(ones(1,prod(pp.d)),:),[pp.d,xn]); |
| 45 c = reshape (pp.P(:,1), pp.n, prod (pp.d)); | |
| 6014 | 46 yi = reshape (c(idx,:).', [pp.d, xn]); |
| 5824 | 47 for i = 2 : pp.k; |
| 48 c = reshape (pp.P(:,i), pp.n, prod (pp.d)); | |
| 6014 | 49 yi = yi .* dx + reshape (c(idx,:).', [pp.d, xn]); |
| 5824 | 50 endfor |
| 51 if (transposed && isscalar (pp.d) && pp.d == 1) | |
| 52 yi = yi.'; | |
| 53 endif | |
| 54 endif | |
| 55 endfunction |