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raw | patch | inline | side by side (parent: f98d93b)
author | johanengelen <johanengelen@users.sourceforge.net> | |
Fri, 31 Aug 2007 08:28:40 +0000 (08:28 +0000) | ||
committer | johanengelen <johanengelen@users.sourceforge.net> | |
Fri, 31 Aug 2007 08:28:40 +0000 (08:28 +0000) |
src/2geom/chebyshev.cpp | [deleted file] | patch | blob | history |
src/2geom/chebyshev.h | [deleted file] | patch | blob | history |
diff --git a/src/2geom/chebyshev.cpp b/src/2geom/chebyshev.cpp
--- a/src/2geom/chebyshev.cpp
+++ /dev/null
@@ -1,126 +0,0 @@
-#include "chebyshev.h"
-
-#include "sbasis.h"
-#include "sbasis-poly.h"
-
-#include <vector>
-using std::vector;
-
-#include <gsl/gsl_math.h>
-#include <gsl/gsl_chebyshev.h>
-
-namespace Geom{
-
-SBasis cheb(unsigned n) {
- static std::vector<SBasis> basis;
- if(basis.empty()) {
- basis.push_back(Linear(1,1));
- basis.push_back(Linear(0,1));
- }
- for(unsigned i = basis.size(); i <= n; i++) {
- basis.push_back(Linear(0,2)*basis[i-1] - basis[i-2]);
- }
-
- return basis[n];
-}
-
-SBasis cheb_series(unsigned n, double* cheb_coeff) {
- SBasis r;
- for(unsigned i = 0; i < n; i++) {
- double cof = cheb_coeff[i];
- //if(i == 0)
- //cof /= 2;
- r += cheb(i)*cof;
- }
-
- return r;
-}
-
-SBasis clenshaw_series(unsigned m, double* cheb_coeff) {
- /** b_n = a_n
- b_n-1 = 2*x*b_n + a_n-1
- b_n-k = 2*x*b_{n-k+1} + a_{n-k} - b_{n - k + 2}
- b_0 = x*b_1 + a_0 - b_2
- */
-
- double a = -1, b = 1;
- SBasis d, dd;
- SBasis y = (Linear(0, 2) - (a+b)) / (b-a);
- SBasis y2 = 2*y;
- for(int j = m - 1; j >= 1; j--) {
- SBasis sv = d;
- d = y2*d - dd + cheb_coeff[j];
- dd = sv;
- }
-
- return y*d - dd + 0.5*cheb_coeff[0];
-}
-
-SBasis chebyshev_approximant (double (*f)(double,void*), int order, Interval in, void* p) {
- gsl_cheb_series *cs = gsl_cheb_alloc (order+2);
-
- gsl_function F;
-
- F.function = f;
- F.params = p;
-
- gsl_cheb_init (cs, &F, in[0], in[1]);
-
- SBasis r = compose(clenshaw_series(order, cs->c), Linear(-1,1));
-
- gsl_cheb_free (cs);
- return r;
-}
-
-struct wrap {
- double (*f)(double,void*);
- void* pp;
- double fa, fb;
- Interval in;
-};
-
-double f_interp(double x, void* p) {
- struct wrap *wr = (struct wrap *)p;
- double z = (x - wr->in[0]) / (wr->in[1] - wr->in[0]);
- return (wr->f)(x, wr->pp) - ((1 - z)*wr->fa + z*wr->fb);
-}
-
-SBasis chebyshev_approximant_interpolating (double (*f)(double,void*),
- int order, Interval in, void* p) {
- double fa = f(in[0], p);
- double fb = f(in[1], p);
- struct wrap wr;
- wr.fa = fa;
- wr.fb = fb;
- wr.in = in;
- printf("%f %f\n", fa, fb);
- wr.f = f;
- wr.pp = p;
- return compose(Linear(in[0], in[1]), Linear(fa, fb)) + chebyshev_approximant(f_interp, order, in, &wr) + Linear(fa, fb);
-}
-
-SBasis chebyshev(unsigned n) {
- static std::vector<SBasis> basis;
- if(basis.empty()) {
- basis.push_back(Linear(1,1));
- basis.push_back(Linear(0,1));
- }
- for(unsigned i = basis.size(); i <= n; i++) {
- basis.push_back(Linear(0,2)*basis[i-1] - basis[i-2]);
- }
-
- return basis[n];
-}
-
-};
-
-/*
- Local Variables:
- mode:c++
- c-file-style:"stroustrup"
- c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
- indent-tabs-mode:nil
- fill-column:99
- End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/2geom/chebyshev.h b/src/2geom/chebyshev.h
--- a/src/2geom/chebyshev.h
+++ /dev/null
@@ -1,30 +0,0 @@
-#ifndef _CHEBYSHEV
-#define _CHEBYSHEV
-
-#include "sbasis.h"
-#include "interval.h"
-
-/*** Conversion between Chebyshev approximation and SBasis.
- *
- */
-
-namespace Geom{
-
-SBasis chebyshev_approximant (double (*f)(double,void*), int order, Interval in, void* p=0);
-SBasis chebyshev_approximant_interpolating (double (*f)(double,void*), int order, Interval in, void* p=0);
-SBasis chebyshev(unsigned n);
-
-};
-
-/*
- Local Variables:
- mode:c++
- c-file-style:"stroustrup"
- c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
- indent-tabs-mode:nil
- fill-column:99
- End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
-
-#endif