120ca87015
git-svn-id: https://free-cad.svn.sourceforge.net/svnroot/free-cad/trunk@5000 e8eeb9e2-ec13-0410-a4a9-efa5cf37419d
114 lines
3.6 KiB
C++
114 lines
3.6 KiB
C++
// Wild Magic Source Code
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// David Eberly
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// http://www.geometrictools.com
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// Copyright (c) 1998-2007
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//
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// This library is free software; you can redistribute it and/or modify it
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// under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation; either version 2.1 of the License, or (at
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// your option) any later version. The license is available for reading at
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// either of the locations:
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// http://www.gnu.org/copyleft/lgpl.html
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// http://www.geometrictools.com/License/WildMagicLicense.pdf
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// The license applies to versions 0 through 4 of Wild Magic.
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//
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// Version: 4.0.0 (2006/06/28)
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#include "Wm4FoundationPCH.h"
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#include "Wm4ApprPolyFit3.h"
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#include "Wm4LinearSystem.h"
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namespace Wm4
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{
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//----------------------------------------------------------------------------
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template <class Real>
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Real* PolyFit3 (int iSamples, const Real* afX, const Real* afY,
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const Real* afW, int iXDegree, int iYDegree)
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{
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int iXBound = iXDegree + 1;
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int iYBound = iYDegree + 1;
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int iQuantity = iXBound*iYBound;
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Real* afCoeff = WM4_NEW Real[iQuantity];
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int i0, j0, i1, j1, iS;
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// powers of x, y
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Real** aafXP;
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Real** aafYP;
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Allocate<Real>(2*iXDegree+1,iSamples,aafXP);
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Allocate<Real>(2*iYDegree+1,iSamples,aafYP);
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for (iS = 0; iS < iSamples; iS++)
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{
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aafXP[iS][0] = (Real)1.0;
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for (i0 = 1; i0 <= 2*iXDegree; i0++)
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{
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aafXP[iS][i0] = afX[iS]*aafXP[iS][i0-1];
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}
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aafYP[iS][0] = (Real)1.0;
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for (j0 = 1; j0 <= 2*iYDegree; j0++)
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{
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aafYP[iS][j0] = afY[iS]*aafYP[iS][j0-1];
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}
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}
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// Vandermonde matrix and right-hand side of linear system
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GMatrix<Real> kA(iQuantity,iQuantity);
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Real* afB = WM4_NEW Real[iQuantity];
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for (j0 = 0; j0 <= iYDegree; j0++)
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{
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for (i0 = 0; i0 <= iXDegree; i0++)
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{
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int iIndex0 = i0+iXBound*j0;
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Real fSum = (Real)0.0;
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for (iS = 0; iS < iSamples; iS++)
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{
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fSum += afW[iS]*aafXP[iS][i0]*aafYP[iS][j0];
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}
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afB[iIndex0] = fSum;
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for (j1 = 0; j1 <= iYDegree; j1++)
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{
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for (i1 = 0; i1 <= iXDegree; i1++)
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{
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int iIndex1 = i1+iXBound*j1;
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fSum = (Real)0.0;
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for (iS = 0; iS < iSamples; iS++)
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{
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fSum += aafXP[iS][i0+i1]*aafYP[iS][j0+j1];
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}
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kA(iIndex0,iIndex1) = fSum;
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}
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}
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}
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}
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// solve for the polynomial coefficients
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bool bHasSolution = LinearSystem<Real>().Solve(kA,afB,afCoeff);
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if (!bHasSolution) throw std::exception();
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assert(bHasSolution);
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(void)bHasSolution; // avoid compiler warning in release build
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WM4_DELETE[] afB;
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Deallocate<Real>(aafXP);
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Deallocate<Real>(aafYP);
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return afCoeff;
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}
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//----------------------------------------------------------------------------
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//----------------------------------------------------------------------------
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// explicit instantiation
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//----------------------------------------------------------------------------
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template WM4_FOUNDATION_ITEM
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float* PolyFit3<float> (int, const float*, const float*, const float*,
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int, int);
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template WM4_FOUNDATION_ITEM
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double* PolyFit3<double> (int, const double*, const double*, const double*,
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int, int);
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//----------------------------------------------------------------------------
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}
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