| 29 | 
  | 
 * @date 10/11/2004 | 
| 30 | 
  | 
 * @version 1.0 | 
| 31 | 
  | 
 */ | 
| 32 | 
< | 
#ifndef MATH_SQUAREMATRIX_HPP  | 
| 32 | 
> | 
 #ifndef MATH_SQUAREMATRIX_HPP  | 
| 33 | 
  | 
#define MATH_SQUAREMATRIX_HPP  | 
| 34 | 
  | 
 | 
| 35 | 
  | 
#include "math/RectMatrix.hpp" | 
| 78 | 
  | 
            return m; | 
| 79 | 
  | 
        } | 
| 80 | 
  | 
 | 
| 81 | 
< | 
        /** Retunrs  the inversion of this matrix. */ | 
| 81 | 
> | 
        /**  | 
| 82 | 
> | 
         * Retunrs  the inversion of this matrix.  | 
| 83 | 
> | 
         * @todo need implementation | 
| 84 | 
> | 
         */ | 
| 85 | 
  | 
         SquareMatrix<Real, Dim>  inverse() { | 
| 86 | 
  | 
             SquareMatrix<Real, Dim> result; | 
| 87 | 
  | 
 | 
| 88 | 
  | 
             return result; | 
| 89 | 
  | 
        }         | 
| 90 | 
  | 
 | 
| 91 | 
< | 
        /** Returns the determinant of this matrix. */ | 
| 92 | 
< | 
        double determinant() const { | 
| 93 | 
< | 
            double det; | 
| 91 | 
> | 
        /** | 
| 92 | 
> | 
         * Returns the determinant of this matrix. | 
| 93 | 
> | 
         * @todo need implementation | 
| 94 | 
> | 
         */ | 
| 95 | 
> | 
        Real determinant() const { | 
| 96 | 
> | 
            Real det; | 
| 97 | 
  | 
            return det; | 
| 98 | 
  | 
        } | 
| 99 | 
  | 
 | 
| 100 | 
  | 
        /** Returns the trace of this matrix. */ | 
| 101 | 
< | 
        double trace() const { | 
| 102 | 
< | 
           double tmp = 0; | 
| 101 | 
> | 
        Real trace() const { | 
| 102 | 
> | 
           Real tmp = 0; | 
| 103 | 
  | 
            | 
| 104 | 
  | 
            for (unsigned int i = 0; i < Dim ; i++) | 
| 105 | 
  | 
                tmp += data_[i][i]; | 
| 148 | 
  | 
            return true; | 
| 149 | 
  | 
        }          | 
| 150 | 
  | 
 | 
| 151 | 
+ | 
        /** @todo need implementation */ | 
| 152 | 
  | 
        void diagonalize() { | 
| 153 | 
< | 
            jacobi(m, eigenValues, ortMat); | 
| 153 | 
> | 
            //jacobi(m, eigenValues, ortMat); | 
| 154 | 
  | 
        } | 
| 155 | 
  | 
 | 
| 156 | 
  | 
        /** | 
| 150 | 
– | 
         * Finds the eigenvalues and eigenvectors of a symmetric matrix | 
| 151 | 
– | 
         * @param eigenvals a reference to a vector3 where the | 
| 152 | 
– | 
         * eigenvalues will be stored. The eigenvalues are ordered so | 
| 153 | 
– | 
         * that eigenvals[0] <= eigenvals[1] <= eigenvals[2]. | 
| 154 | 
– | 
         * @return an orthogonal matrix whose ith column is an | 
| 155 | 
– | 
         * eigenvector for the eigenvalue eigenvals[i] | 
| 156 | 
– | 
         */ | 
| 157 | 
– | 
        SquareMatrix<Real, Dim>  findEigenvectors(Vector<Real, Dim>& eigenValues) { | 
| 158 | 
– | 
            SquareMatrix<Real, Dim> ortMat; | 
| 159 | 
– | 
             | 
| 160 | 
– | 
            if ( !isSymmetric()){ | 
| 161 | 
– | 
                throw(); | 
| 162 | 
– | 
            } | 
| 163 | 
– | 
             | 
| 164 | 
– | 
            SquareMatrix<Real, Dim> m(*this); | 
| 165 | 
– | 
            jacobi(m, eigenValues, ortMat); | 
| 166 | 
– | 
 | 
| 167 | 
– | 
            return ortMat; | 
| 168 | 
– | 
        } | 
| 169 | 
– | 
        /** | 
| 157 | 
  | 
         * Jacobi iteration routines for computing eigenvalues/eigenvectors of  | 
| 158 | 
  | 
         * real symmetric matrix | 
| 159 | 
  | 
         * | 
| 160 | 
  | 
         * @return true if success, otherwise return false | 
| 161 | 
< | 
         * @param a source matrix | 
| 162 | 
< | 
         * @param w output eigenvalues  | 
| 163 | 
< | 
         * @param v output eigenvectors  | 
| 161 | 
> | 
         * @param a symmetric matrix whose eigenvectors are to be computed. On return, the matrix is | 
| 162 | 
> | 
         *     overwritten | 
| 163 | 
> | 
         * @param w will contain the eigenvalues of the matrix On return of this function | 
| 164 | 
> | 
         * @param v the columns of this matrix will contain the eigenvectors. The eigenvectors are  | 
| 165 | 
> | 
         *    normalized and mutually orthogonal.  | 
| 166 | 
  | 
         */ | 
| 167 | 
< | 
        bool jacobi(const SquareMatrix<Real, Dim>& a, Vector<Real, Dim>& w,  | 
| 167 | 
> | 
        | 
| 168 | 
> | 
        static int jacobi(SquareMatrix<Real, Dim>& a, Vector<Real, Dim>& d,  | 
| 169 | 
  | 
                              SquareMatrix<Real, Dim>& v); | 
| 170 | 
  | 
    };//end SquareMatrix | 
| 171 | 
  | 
 | 
| 172 | 
  | 
 | 
| 173 | 
< | 
#define ROT(a,i,j,k,l) g=a(i, j);h=a(k, l);a(i, j)=g-s*(h+g*tau);a(k, l)=h+s*(g-h*tau) | 
| 184 | 
< | 
#define MAX_ROTATIONS 60 | 
| 173 | 
> | 
/*========================================================================= | 
| 174 | 
  | 
 | 
| 175 | 
< | 
template<typename Real, int Dim> | 
| 176 | 
< | 
bool SquareMatrix<Real, Dim>::jacobi(const SquareMatrix<Real, Dim>& a, Vector<Real, Dim>& w,  | 
| 188 | 
< | 
                              SquareMatrix<Real, Dim>& v) { | 
| 189 | 
< | 
    const int N = Dim;                                                                        | 
| 190 | 
< | 
    int i, j, k, iq, ip; | 
| 191 | 
< | 
    double tresh, theta, tau, t, sm, s, h, g, c; | 
| 192 | 
< | 
    double tmp; | 
| 193 | 
< | 
    Vector<Real, Dim> b, z; | 
| 175 | 
> | 
  Program:   Visualization Toolkit | 
| 176 | 
> | 
  Module:    $RCSfile: SquareMatrix.hpp,v $ | 
| 177 | 
  | 
 | 
| 178 | 
< | 
    // initialize | 
| 179 | 
< | 
    for (ip=0; ip<N; ip++)  | 
| 180 | 
< | 
    { | 
| 198 | 
< | 
        for (iq=0; iq<N; iq++) v(ip, iq) = 0.0; | 
| 199 | 
< | 
        v(ip, ip) = 1.0; | 
| 200 | 
< | 
    } | 
| 201 | 
< | 
    for (ip=0; ip<N; ip++)  | 
| 202 | 
< | 
    { | 
| 203 | 
< | 
        b(ip) = w(ip) = a(ip, ip); | 
| 204 | 
< | 
        z(ip) = 0.0; | 
| 205 | 
< | 
    } | 
| 178 | 
> | 
  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen | 
| 179 | 
> | 
  All rights reserved. | 
| 180 | 
> | 
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details. | 
| 181 | 
  | 
 | 
| 182 | 
< | 
    // begin rotation sequence | 
| 183 | 
< | 
    for (i=0; i<MAX_ROTATIONS; i++)  | 
| 184 | 
< | 
    { | 
| 210 | 
< | 
        sm = 0.0; | 
| 211 | 
< | 
        for (ip=0; ip<2; ip++)  | 
| 212 | 
< | 
        { | 
| 213 | 
< | 
            for (iq=ip+1; iq<N; iq++) sm += fabs(a(ip, iq)); | 
| 214 | 
< | 
        } | 
| 215 | 
< | 
        if (sm == 0.0) break; | 
| 182 | 
> | 
     This software is distributed WITHOUT ANY WARRANTY; without even | 
| 183 | 
> | 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR | 
| 184 | 
> | 
     PURPOSE.  See the above copyright notice for more information. | 
| 185 | 
  | 
 | 
| 186 | 
< | 
        if (i < 4) tresh = 0.2*sm/(9); | 
| 218 | 
< | 
        else tresh = 0.0; | 
| 186 | 
> | 
=========================================================================*/ | 
| 187 | 
  | 
 | 
| 188 | 
< | 
        for (ip=0; ip<2; ip++)  | 
| 189 | 
< | 
        { | 
| 222 | 
< | 
            for (iq=ip+1; iq<N; iq++)  | 
| 223 | 
< | 
            { | 
| 224 | 
< | 
                g = 100.0*fabs(a(ip, iq)); | 
| 225 | 
< | 
                if (i > 4 && (fabs(w(ip))+g) == fabs(w(ip)) | 
| 226 | 
< | 
                    && (fabs(w(iq))+g) == fabs(w(iq))) | 
| 227 | 
< | 
                { | 
| 228 | 
< | 
                    a(ip, iq) = 0.0; | 
| 229 | 
< | 
                } | 
| 230 | 
< | 
                else if (fabs(a(ip, iq)) > tresh)  | 
| 231 | 
< | 
                { | 
| 232 | 
< | 
                    h = w(iq) - w(ip); | 
| 233 | 
< | 
                    if ( (fabs(h)+g) == fabs(h)) t = (a(ip, iq)) / h; | 
| 234 | 
< | 
                    else  | 
| 235 | 
< | 
                    { | 
| 236 | 
< | 
                        theta = 0.5*h / (a(ip, iq)); | 
| 237 | 
< | 
                        t = 1.0 / (fabs(theta)+sqrt(1.0+theta*theta)); | 
| 238 | 
< | 
                        if (theta < 0.0) t = -t; | 
| 239 | 
< | 
                    } | 
| 240 | 
< | 
                    c = 1.0 / sqrt(1+t*t); | 
| 241 | 
< | 
                    s = t*c; | 
| 242 | 
< | 
                    tau = s/(1.0+c); | 
| 243 | 
< | 
                    h = t*a(ip, iq); | 
| 244 | 
< | 
                    z(ip) -= h; | 
| 245 | 
< | 
                    z(iq) += h; | 
| 246 | 
< | 
                    w(ip) -= h; | 
| 247 | 
< | 
                    w(iq) += h; | 
| 248 | 
< | 
                    a(ip, iq)=0.0; | 
| 249 | 
< | 
                    for (j=0;j<ip-1;j++)  | 
| 250 | 
< | 
                    { | 
| 251 | 
< | 
                        ROT(a,j,ip,j,iq); | 
| 252 | 
< | 
                    } | 
| 253 | 
< | 
                    for (j=ip+1;j<iq-1;j++)  | 
| 254 | 
< | 
                    { | 
| 255 | 
< | 
                        ROT(a,ip,j,j,iq); | 
| 256 | 
< | 
                    } | 
| 257 | 
< | 
                    for (j=iq+1; j<N; j++)  | 
| 258 | 
< | 
                    { | 
| 259 | 
< | 
                        ROT(a,ip,j,iq,j); | 
| 260 | 
< | 
                    } | 
| 261 | 
< | 
                    for (j=0; j<N; j++)  | 
| 262 | 
< | 
                    { | 
| 263 | 
< | 
                        ROT(v,j,ip,j,iq); | 
| 264 | 
< | 
                    } | 
| 265 | 
< | 
                } | 
| 266 | 
< | 
            } | 
| 267 | 
< | 
        } | 
| 188 | 
> | 
#define VTK_ROTATE(a,i,j,k,l) g=a(i, j);h=a(k, l);a(i, j)=g-s*(h+g*tau);\ | 
| 189 | 
> | 
        a(k, l)=h+s*(g-h*tau) | 
| 190 | 
  | 
 | 
| 191 | 
< | 
        for (ip=0; ip<N; ip++)  | 
| 270 | 
< | 
        { | 
| 271 | 
< | 
            b(ip) += z(ip); | 
| 272 | 
< | 
            w(ip) = b(ip); | 
| 273 | 
< | 
            z(ip) = 0.0; | 
| 274 | 
< | 
        } | 
| 275 | 
< | 
    } | 
| 191 | 
> | 
#define VTK_MAX_ROTATIONS 20 | 
| 192 | 
  | 
 | 
| 193 | 
< | 
    if ( i >= MAX_ROTATIONS ) | 
| 194 | 
< | 
        return false; | 
| 193 | 
> | 
    // Jacobi iteration for the solution of eigenvectors/eigenvalues of a nxn | 
| 194 | 
> | 
    // real symmetric matrix. Square nxn matrix a; size of matrix in n; | 
| 195 | 
> | 
    // output eigenvalues in w; and output eigenvectors in v. Resulting | 
| 196 | 
> | 
    // eigenvalues/vectors are sorted in decreasing order; eigenvectors are | 
| 197 | 
> | 
    // normalized. | 
| 198 | 
> | 
    template<typename Real, int Dim> | 
| 199 | 
> | 
    int SquareMatrix<Real, Dim>::jacobi(SquareMatrix<Real, Dim>& a, Vector<Real, Dim>& w,  | 
| 200 | 
> | 
                                  SquareMatrix<Real, Dim>& v) { | 
| 201 | 
> | 
      const int n = Dim;   | 
| 202 | 
> | 
      int i, j, k, iq, ip, numPos; | 
| 203 | 
> | 
      Real tresh, theta, tau, t, sm, s, h, g, c, tmp; | 
| 204 | 
> | 
      Real bspace[4], zspace[4]; | 
| 205 | 
> | 
      Real *b = bspace; | 
| 206 | 
> | 
      Real *z = zspace; | 
| 207 | 
  | 
 | 
| 208 | 
< | 
    // sort eigenfunctions | 
| 209 | 
< | 
    for (j=0; j<N; j++)  | 
| 210 | 
< | 
    { | 
| 211 | 
< | 
        k = j; | 
| 212 | 
< | 
        tmp = w(k); | 
| 213 | 
< | 
        for (i=j; i<N; i++) | 
| 286 | 
< | 
        { | 
| 287 | 
< | 
            if (w(i) >= tmp)  | 
| 288 | 
< | 
            { | 
| 289 | 
< | 
                k = i; | 
| 290 | 
< | 
                tmp = w(k); | 
| 291 | 
< | 
            } | 
| 292 | 
< | 
        } | 
| 293 | 
< | 
        if (k != j)  | 
| 294 | 
< | 
        { | 
| 295 | 
< | 
            w(k) = w(j); | 
| 296 | 
< | 
            w(j) = tmp; | 
| 297 | 
< | 
            for (i=0; i<N; i++)  | 
| 298 | 
< | 
            { | 
| 299 | 
< | 
                tmp = v(i, j); | 
| 300 | 
< | 
                v(i, j) = v(i, k); | 
| 301 | 
< | 
                v(i, k) = tmp; | 
| 302 | 
< | 
            } | 
| 303 | 
< | 
        } | 
| 304 | 
< | 
    } | 
| 208 | 
> | 
      // only allocate memory if the matrix is large | 
| 209 | 
> | 
      if (n > 4) | 
| 210 | 
> | 
        { | 
| 211 | 
> | 
        b = new Real[n]; | 
| 212 | 
> | 
        z = new Real[n];  | 
| 213 | 
> | 
        } | 
| 214 | 
  | 
 | 
| 215 | 
< | 
    //    insure eigenvector consistency (i.e., Jacobi can compute | 
| 216 | 
< | 
    //    vectors that are negative of one another (.707,.707,0) and | 
| 217 | 
< | 
    //    (-.707,-.707,0). This can reek havoc in | 
| 218 | 
< | 
    //    hyperstreamline/other stuff. We will select the most | 
| 219 | 
< | 
    //    positive eigenvector. | 
| 220 | 
< | 
    int numPos; | 
| 221 | 
< | 
    for (j=0; j<N; j++) | 
| 222 | 
< | 
    { | 
| 223 | 
< | 
        for (numPos=0, i=0; i<N; i++) if ( v(i, j) >= 0.0 ) numPos++; | 
| 224 | 
< | 
        if ( numPos < 2 ) for(i=0; i<N; i++) v(i, j) *= -1.0; | 
| 225 | 
< | 
    } | 
| 215 | 
> | 
      // initialize | 
| 216 | 
> | 
      for (ip=0; ip<n; ip++)  | 
| 217 | 
> | 
        { | 
| 218 | 
> | 
        for (iq=0; iq<n; iq++) | 
| 219 | 
> | 
          { | 
| 220 | 
> | 
          v(ip, iq) = 0.0; | 
| 221 | 
> | 
          } | 
| 222 | 
> | 
        v(ip, ip) = 1.0; | 
| 223 | 
> | 
        } | 
| 224 | 
> | 
      for (ip=0; ip<n; ip++)  | 
| 225 | 
> | 
        { | 
| 226 | 
> | 
        b[ip] = w[ip] = a(ip, ip); | 
| 227 | 
> | 
        z[ip] = 0.0; | 
| 228 | 
> | 
        } | 
| 229 | 
  | 
 | 
| 230 | 
< | 
    return true; | 
| 231 | 
< | 
} | 
| 230 | 
> | 
      // begin rotation sequence | 
| 231 | 
> | 
      for (i=0; i<VTK_MAX_ROTATIONS; i++)  | 
| 232 | 
> | 
        { | 
| 233 | 
> | 
        sm = 0.0; | 
| 234 | 
> | 
        for (ip=0; ip<n-1; ip++)  | 
| 235 | 
> | 
          { | 
| 236 | 
> | 
          for (iq=ip+1; iq<n; iq++) | 
| 237 | 
> | 
            { | 
| 238 | 
> | 
            sm += fabs(a(ip, iq)); | 
| 239 | 
> | 
            } | 
| 240 | 
> | 
          } | 
| 241 | 
> | 
        if (sm == 0.0) | 
| 242 | 
> | 
          { | 
| 243 | 
> | 
          break; | 
| 244 | 
> | 
          } | 
| 245 | 
  | 
 | 
| 246 | 
< | 
#undef ROT | 
| 247 | 
< | 
#undef MAX_ROTATIONS | 
| 246 | 
> | 
        if (i < 3)                                // first 3 sweeps | 
| 247 | 
> | 
          { | 
| 248 | 
> | 
          tresh = 0.2*sm/(n*n); | 
| 249 | 
> | 
          } | 
| 250 | 
> | 
        else | 
| 251 | 
> | 
          { | 
| 252 | 
> | 
          tresh = 0.0; | 
| 253 | 
> | 
          } | 
| 254 | 
  | 
 | 
| 255 | 
< | 
} | 
| 255 | 
> | 
        for (ip=0; ip<n-1; ip++)  | 
| 256 | 
> | 
          { | 
| 257 | 
> | 
          for (iq=ip+1; iq<n; iq++)  | 
| 258 | 
> | 
            { | 
| 259 | 
> | 
            g = 100.0*fabs(a(ip, iq)); | 
| 260 | 
  | 
 | 
| 261 | 
+ | 
            // after 4 sweeps | 
| 262 | 
+ | 
            if (i > 3 && (fabs(w[ip])+g) == fabs(w[ip]) | 
| 263 | 
+ | 
            && (fabs(w[iq])+g) == fabs(w[iq])) | 
| 264 | 
+ | 
              { | 
| 265 | 
+ | 
              a(ip, iq) = 0.0; | 
| 266 | 
+ | 
              } | 
| 267 | 
+ | 
            else if (fabs(a(ip, iq)) > tresh)  | 
| 268 | 
+ | 
              { | 
| 269 | 
+ | 
              h = w[iq] - w[ip]; | 
| 270 | 
+ | 
              if ( (fabs(h)+g) == fabs(h)) | 
| 271 | 
+ | 
                { | 
| 272 | 
+ | 
                t = (a(ip, iq)) / h; | 
| 273 | 
+ | 
                } | 
| 274 | 
+ | 
              else  | 
| 275 | 
+ | 
                { | 
| 276 | 
+ | 
                theta = 0.5*h / (a(ip, iq)); | 
| 277 | 
+ | 
                t = 1.0 / (fabs(theta)+sqrt(1.0+theta*theta)); | 
| 278 | 
+ | 
                if (theta < 0.0) | 
| 279 | 
+ | 
                  { | 
| 280 | 
+ | 
                  t = -t; | 
| 281 | 
+ | 
                  } | 
| 282 | 
+ | 
                } | 
| 283 | 
+ | 
              c = 1.0 / sqrt(1+t*t); | 
| 284 | 
+ | 
              s = t*c; | 
| 285 | 
+ | 
              tau = s/(1.0+c); | 
| 286 | 
+ | 
              h = t*a(ip, iq); | 
| 287 | 
+ | 
              z[ip] -= h; | 
| 288 | 
+ | 
              z[iq] += h; | 
| 289 | 
+ | 
              w[ip] -= h; | 
| 290 | 
+ | 
              w[iq] += h; | 
| 291 | 
+ | 
              a(ip, iq)=0.0; | 
| 292 | 
+ | 
 | 
| 293 | 
+ | 
              // ip already shifted left by 1 unit | 
| 294 | 
+ | 
              for (j = 0;j <= ip-1;j++)  | 
| 295 | 
+ | 
                { | 
| 296 | 
+ | 
                VTK_ROTATE(a,j,ip,j,iq); | 
| 297 | 
+ | 
                } | 
| 298 | 
+ | 
              // ip and iq already shifted left by 1 unit | 
| 299 | 
+ | 
              for (j = ip+1;j <= iq-1;j++)  | 
| 300 | 
+ | 
                { | 
| 301 | 
+ | 
                VTK_ROTATE(a,ip,j,j,iq); | 
| 302 | 
+ | 
                } | 
| 303 | 
+ | 
              // iq already shifted left by 1 unit | 
| 304 | 
+ | 
              for (j=iq+1; j<n; j++)  | 
| 305 | 
+ | 
                { | 
| 306 | 
+ | 
                VTK_ROTATE(a,ip,j,iq,j); | 
| 307 | 
+ | 
                } | 
| 308 | 
+ | 
              for (j=0; j<n; j++)  | 
| 309 | 
+ | 
                { | 
| 310 | 
+ | 
                VTK_ROTATE(v,j,ip,j,iq); | 
| 311 | 
+ | 
                } | 
| 312 | 
+ | 
              } | 
| 313 | 
+ | 
            } | 
| 314 | 
+ | 
          } | 
| 315 | 
+ | 
 | 
| 316 | 
+ | 
        for (ip=0; ip<n; ip++)  | 
| 317 | 
+ | 
          { | 
| 318 | 
+ | 
          b[ip] += z[ip]; | 
| 319 | 
+ | 
          w[ip] = b[ip]; | 
| 320 | 
+ | 
          z[ip] = 0.0; | 
| 321 | 
+ | 
          } | 
| 322 | 
+ | 
        } | 
| 323 | 
+ | 
 | 
| 324 | 
+ | 
      //// this is NEVER called | 
| 325 | 
+ | 
      if ( i >= VTK_MAX_ROTATIONS ) | 
| 326 | 
+ | 
        { | 
| 327 | 
+ | 
           std::cout << "vtkMath::Jacobi: Error extracting eigenfunctions" << std::endl; | 
| 328 | 
+ | 
           return 0; | 
| 329 | 
+ | 
        } | 
| 330 | 
+ | 
 | 
| 331 | 
+ | 
      // sort eigenfunctions                 these changes do not affect accuracy  | 
| 332 | 
+ | 
      for (j=0; j<n-1; j++)                  // boundary incorrect | 
| 333 | 
+ | 
        { | 
| 334 | 
+ | 
        k = j; | 
| 335 | 
+ | 
        tmp = w[k]; | 
| 336 | 
+ | 
        for (i=j+1; i<n; i++)                // boundary incorrect, shifted already | 
| 337 | 
+ | 
          { | 
| 338 | 
+ | 
          if (w[i] >= tmp)                   // why exchage if same? | 
| 339 | 
+ | 
            { | 
| 340 | 
+ | 
            k = i; | 
| 341 | 
+ | 
            tmp = w[k]; | 
| 342 | 
+ | 
            } | 
| 343 | 
+ | 
          } | 
| 344 | 
+ | 
        if (k != j)  | 
| 345 | 
+ | 
          { | 
| 346 | 
+ | 
          w[k] = w[j]; | 
| 347 | 
+ | 
          w[j] = tmp; | 
| 348 | 
+ | 
          for (i=0; i<n; i++)  | 
| 349 | 
+ | 
            { | 
| 350 | 
+ | 
            tmp = v(i, j); | 
| 351 | 
+ | 
            v(i, j) = v(i, k); | 
| 352 | 
+ | 
            v(i, k) = tmp; | 
| 353 | 
+ | 
            } | 
| 354 | 
+ | 
          } | 
| 355 | 
+ | 
        } | 
| 356 | 
+ | 
      // insure eigenvector consistency (i.e., Jacobi can compute vectors that | 
| 357 | 
+ | 
      // are negative of one another (.707,.707,0) and (-.707,-.707,0). This can | 
| 358 | 
+ | 
      // reek havoc in hyperstreamline/other stuff. We will select the most | 
| 359 | 
+ | 
      // positive eigenvector. | 
| 360 | 
+ | 
      int ceil_half_n = (n >> 1) + (n & 1); | 
| 361 | 
+ | 
      for (j=0; j<n; j++) | 
| 362 | 
+ | 
        { | 
| 363 | 
+ | 
        for (numPos=0, i=0; i<n; i++) | 
| 364 | 
+ | 
          { | 
| 365 | 
+ | 
          if ( v(i, j) >= 0.0 ) | 
| 366 | 
+ | 
            { | 
| 367 | 
+ | 
            numPos++; | 
| 368 | 
+ | 
            } | 
| 369 | 
+ | 
          } | 
| 370 | 
+ | 
    //    if ( numPos < ceil(double(n)/double(2.0)) ) | 
| 371 | 
+ | 
        if ( numPos < ceil_half_n) | 
| 372 | 
+ | 
          { | 
| 373 | 
+ | 
          for(i=0; i<n; i++) | 
| 374 | 
+ | 
            { | 
| 375 | 
+ | 
            v(i, j) *= -1.0; | 
| 376 | 
+ | 
            } | 
| 377 | 
+ | 
          } | 
| 378 | 
+ | 
        } | 
| 379 | 
+ | 
 | 
| 380 | 
+ | 
      if (n > 4) | 
| 381 | 
+ | 
        { | 
| 382 | 
+ | 
        delete [] b; | 
| 383 | 
+ | 
        delete [] z; | 
| 384 | 
+ | 
        } | 
| 385 | 
+ | 
      return 1; | 
| 386 | 
+ | 
    } | 
| 387 | 
+ | 
 | 
| 388 | 
+ | 
 | 
| 389 | 
+ | 
} | 
| 390 | 
  | 
#endif //MATH_SQUAREMATRIX_HPP  | 
| 391 | 
+ | 
 |