]> www.ginac.de Git - ginac.git/blobdiff - ginac/matrix.cpp
Fixed initialization order bug (references to flyweights removed!) [C.Dams].
[ginac.git] / ginac / matrix.cpp
index 9dc46de92776ff3a8988d40e76b92e10c6effe03..3cc20039e9f66e103ee4c1d19bd1fa36806e0aaf 100644 (file)
@@ -3,7 +3,7 @@
  *  Implementation of symbolic matrices */
 
 /*
- *  GiNaC Copyright (C) 1999-2003 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2005 Johannes Gutenberg University Mainz, Germany
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -17,7 +17,7 @@
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
 #include <string>
@@ -45,7 +45,7 @@ namespace GiNaC {
 GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(matrix, basic,
   print_func<print_context>(&matrix::do_print).
   print_func<print_latex>(&matrix::do_print_latex).
-  print_func<print_tree>(&basic::do_print_tree).
+  print_func<print_tree>(&matrix::do_print_tree).
   print_func<print_python_repr>(&matrix::do_print_python_repr))
 
 //////////
@@ -234,6 +234,34 @@ ex matrix::subs(const exmap & mp, unsigned options) const
        return matrix(row, col, m2).subs_one_level(mp, options);
 }
 
+/** Complex conjugate every matrix entry. */
+ex matrix::conjugate() const
+{
+       exvector * ev = 0;
+       for (exvector::const_iterator i=m.begin(); i!=m.end(); ++i) {
+               ex x = i->conjugate();
+               if (ev) {
+                       ev->push_back(x);
+                       continue;
+               }
+               if (are_ex_trivially_equal(x, *i)) {
+                       continue;
+               }
+               ev = new exvector;
+               ev->reserve(m.size());
+               for (exvector::const_iterator j=m.begin(); j!=i; ++j) {
+                       ev->push_back(*j);
+               }
+               ev->push_back(x);
+       }
+       if (ev) {
+               ex result = matrix(row, col, *ev);
+               delete ev;
+               return result;
+       }
+       return *this;
+}
+
 // protected
 
 int matrix::compare_same_type(const basic & other) const
@@ -619,12 +647,12 @@ matrix matrix::pow(const ex & expn) const
                        // that this is not entirely optimal but close to optimal and
                        // "better" algorithms are much harder to implement.  (See Knuth,
                        // TAoCP2, section "Evaluation of Powers" for a good discussion.)
-                       while (b!=_num1) {
+                       while (b!=*_num1_p) {
                                if (b.is_odd()) {
                                        C = C.mul(A);
                                        --b;
                                }
-                               b /= _num2;  // still integer.
+                               b /= *_num2_p;  // still integer.
                                A = A.mul(A);
                        }
                        return A.mul(C);
@@ -736,7 +764,7 @@ ex matrix::determinant(unsigned algo) const
                else
                        return m[0].expand();
        }
-       
+
        // Compute the determinant
        switch(algo) {
                case determinant_algo::gauss: {
@@ -832,7 +860,7 @@ ex matrix::trace() const
                tr += m[r*col+r];
        
        if (tr.info(info_flags::rational_function) &&
-               !tr.info(info_flags::crational_polynomial))
+          !tr.info(info_flags::crational_polynomial))
                return tr.normal();
        else
                return tr.expand();
@@ -938,14 +966,15 @@ matrix matrix::inverse() const
  *
  *  @param vars n x p matrix, all elements must be symbols 
  *  @param rhs m x p matrix
+ *  @param algo selects the solving algorithm
  *  @return n x p solution matrix
  *  @exception logic_error (incompatible matrices)
  *  @exception invalid_argument (1st argument must be matrix of symbols)
  *  @exception runtime_error (inconsistent linear system)
  *  @see       solve_algo */
 matrix matrix::solve(const matrix & vars,
-                                        const matrix & rhs,
-                                        unsigned algo) const
+                     const matrix & rhs,
+                     unsigned algo) const
 {
        const unsigned m = this->rows();
        const unsigned n = this->cols();
@@ -1038,6 +1067,29 @@ matrix matrix::solve(const matrix & vars,
 }
 
 
+/** Compute the rank of this matrix. */
+unsigned matrix::rank() const
+{
+       // Method:
+       // Transform this matrix into upper echelon form and then count the
+       // number of non-zero rows.
+
+       GINAC_ASSERT(row*col==m.capacity());
+
+       // Actually, any elimination scheme will do since we are only
+       // interested in the echelon matrix' zeros.
+       matrix to_eliminate = *this;
+       to_eliminate.fraction_free_elimination();
+
+       unsigned r = row*col;  // index of last non-zero element
+       while (r--) {
+               if (!to_eliminate.m[r].is_zero())
+                       return 1+r/col;
+       }
+       return 0;
+}
+
+
 // protected
 
 /** Recursive determinant for small matrices having at least one symbolic
@@ -1153,7 +1205,7 @@ ex matrix::determinant_minor() const
                                        Pkey[j] = Pkey[j-1]+1;
                } while(fc);
                // next column, so change the role of A and B:
-               A = B;
+               A.swap(B);
                B.clear();
        }
        
@@ -1179,8 +1231,8 @@ int matrix::gauss_elimination(const bool det)
        int sign = 1;
        
        unsigned r0 = 0;
-       for (unsigned r1=0; (r1<n-1)&&(r0<m-1); ++r1) {
-               int indx = pivot(r0, r1, true);
+       for (unsigned c0=0; c0<n && r0<m-1; ++c0) {
+               int indx = pivot(r0, c0, true);
                if (indx == -1) {
                        sign = 0;
                        if (det)
@@ -1190,17 +1242,17 @@ int matrix::gauss_elimination(const bool det)
                        if (indx > 0)
                                sign = -sign;
                        for (unsigned r2=r0+1; r2<m; ++r2) {
-                               if (!this->m[r2*n+r1].is_zero()) {
+                               if (!this->m[r2*n+c0].is_zero()) {
                                        // yes, there is something to do in this row
-                                       ex piv = this->m[r2*n+r1] / this->m[r0*n+r1];
-                                       for (unsigned c=r1+1; c<n; ++c) {
+                                       ex piv = this->m[r2*n+c0] / this->m[r0*n+c0];
+                                       for (unsigned c=c0+1; c<n; ++c) {
                                                this->m[r2*n+c] -= piv * this->m[r0*n+c];
                                                if (!this->m[r2*n+c].info(info_flags::numeric))
                                                        this->m[r2*n+c] = this->m[r2*n+c].normal();
                                        }
                                }
                                // fill up left hand side with zeros
-                               for (unsigned c=0; c<=r1; ++c)
+                               for (unsigned c=r0; c<=c0; ++c)
                                        this->m[r2*n+c] = _ex0;
                        }
                        if (det) {
@@ -1211,7 +1263,12 @@ int matrix::gauss_elimination(const bool det)
                        ++r0;
                }
        }
-       
+       // clear remaining rows
+       for (unsigned r=r0+1; r<m; ++r) {
+               for (unsigned c=0; c<n; ++c)
+                       this->m[r*n+c] = _ex0;
+       }
+
        return sign;
 }
 
@@ -1233,8 +1290,8 @@ int matrix::division_free_elimination(const bool det)
        int sign = 1;
        
        unsigned r0 = 0;
-       for (unsigned r1=0; (r1<n-1)&&(r0<m-1); ++r1) {
-               int indx = pivot(r0, r1, true);
+       for (unsigned c0=0; c0<n && r0<m-1; ++c0) {
+               int indx = pivot(r0, c0, true);
                if (indx==-1) {
                        sign = 0;
                        if (det)
@@ -1244,10 +1301,10 @@ int matrix::division_free_elimination(const bool det)
                        if (indx>0)
                                sign = -sign;
                        for (unsigned r2=r0+1; r2<m; ++r2) {
-                               for (unsigned c=r1+1; c<n; ++c)
-                                       this->m[r2*n+c] = (this->m[r0*n+r1]*this->m[r2*n+c] - this->m[r2*n+r1]*this->m[r0*n+c]).expand();
+                               for (unsigned c=c0+1; c<n; ++c)
+                                       this->m[r2*n+c] = (this->m[r0*n+c0]*this->m[r2*n+c] - this->m[r2*n+c0]*this->m[r0*n+c]).expand();
                                // fill up left hand side with zeros
-                               for (unsigned c=0; c<=r1; ++c)
+                               for (unsigned c=r0; c<=c0; ++c)
                                        this->m[r2*n+c] = _ex0;
                        }
                        if (det) {
@@ -1258,7 +1315,12 @@ int matrix::division_free_elimination(const bool det)
                        ++r0;
                }
        }
-       
+       // clear remaining rows
+       for (unsigned r=r0+1; r<m; ++r) {
+               for (unsigned c=0; c<n; ++c)
+                       this->m[r*n+c] = _ex0;
+       }
+
        return sign;
 }
 
@@ -1331,8 +1393,8 @@ int matrix::fraction_free_elimination(const bool det)
        }
        
        unsigned r0 = 0;
-       for (unsigned r1=0; (r1<n-1)&&(r0<m-1); ++r1) {
-               int indx = tmp_n.pivot(r0, r1, true);
+       for (unsigned c0=0; c0<n && r0<m-1; ++c0) {
+               int indx = tmp_n.pivot(r0, c0, true);
                if (indx==-1) {
                        sign = 0;
                        if (det)
@@ -1342,17 +1404,17 @@ int matrix::fraction_free_elimination(const bool det)
                        if (indx>0) {
                                sign = -sign;
                                // tmp_n's rows r0 and indx were swapped, do the same in tmp_d:
-                               for (unsigned c=r1; c<n; ++c)
+                               for (unsigned c=c0; c<n; ++c)
                                        tmp_d.m[n*indx+c].swap(tmp_d.m[n*r0+c]);
                        }
                        for (unsigned r2=r0+1; r2<m; ++r2) {
-                               for (unsigned c=r1+1; c<n; ++c) {
-                                       dividend_n = (tmp_n.m[r0*n+r1]*tmp_n.m[r2*n+c]*
-                                                     tmp_d.m[r2*n+r1]*tmp_d.m[r0*n+c]
-                                                    -tmp_n.m[r2*n+r1]*tmp_n.m[r0*n+c]*
-                                                     tmp_d.m[r0*n+r1]*tmp_d.m[r2*n+c]).expand();
-                                       dividend_d = (tmp_d.m[r2*n+r1]*tmp_d.m[r0*n+c]*
-                                                     tmp_d.m[r0*n+r1]*tmp_d.m[r2*n+c]).expand();
+                               for (unsigned c=c0+1; c<n; ++c) {
+                                       dividend_n = (tmp_n.m[r0*n+c0]*tmp_n.m[r2*n+c]*
+                                                     tmp_d.m[r2*n+c0]*tmp_d.m[r0*n+c]
+                                                    -tmp_n.m[r2*n+c0]*tmp_n.m[r0*n+c]*
+                                                     tmp_d.m[r0*n+c0]*tmp_d.m[r2*n+c]).expand();
+                                       dividend_d = (tmp_d.m[r2*n+c0]*tmp_d.m[r0*n+c]*
+                                                     tmp_d.m[r0*n+c0]*tmp_d.m[r2*n+c]).expand();
                                        bool check = divide(dividend_n, divisor_n,
                                                            tmp_n.m[r2*n+c], true);
                                        check &= divide(dividend_d, divisor_d,
@@ -1360,13 +1422,13 @@ int matrix::fraction_free_elimination(const bool det)
                                        GINAC_ASSERT(check);
                                }
                                // fill up left hand side with zeros
-                               for (unsigned c=0; c<=r1; ++c)
+                               for (unsigned c=r0; c<=c0; ++c)
                                        tmp_n.m[r2*n+c] = _ex0;
                        }
-                       if ((r1<n-1)&&(r0<m-1)) {
+                       if (c0<n && r0<m-1) {
                                // compute next iteration's divisor
-                               divisor_n = tmp_n.m[r0*n+r1].expand();
-                               divisor_d = tmp_d.m[r0*n+r1].expand();
+                               divisor_n = tmp_n.m[r0*n+c0].expand();
+                               divisor_d = tmp_d.m[r0*n+c0].expand();
                                if (det) {
                                        // save space by deleting no longer needed elements
                                        for (unsigned c=0; c<n; ++c) {
@@ -1378,6 +1440,12 @@ int matrix::fraction_free_elimination(const bool det)
                        ++r0;
                }
        }
+       // clear remaining rows
+       for (unsigned r=r0+1; r<m; ++r) {
+               for (unsigned c=0; c<n; ++c)
+                       tmp_n.m[r*n+c] = _ex0;
+       }
+
        // repopulate *this matrix:
        exvector::iterator it = this->m.begin(), itend = this->m.end();
        tmp_n_it = tmp_n.m.begin();