* Implementation of symbolic matrices */
/*
- * GiNaC Copyright (C) 1999-2004 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2007 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
*
* 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>
//////////
/** Default ctor. Initializes to 1 x 1-dimensional zero-matrix. */
-matrix::matrix() : inherited(TINFO_matrix), row(1), col(1), m(1, _ex0)
+matrix::matrix() : inherited(&matrix::tinfo_static), row(1), col(1), m(1, _ex0)
{
setflag(status_flags::not_shareable);
}
* @param r number of rows
* @param c number of cols */
matrix::matrix(unsigned r, unsigned c)
- : inherited(TINFO_matrix), row(r), col(c), m(r*c, _ex0)
+ : inherited(&matrix::tinfo_static), row(r), col(c), m(r*c, _ex0)
{
setflag(status_flags::not_shareable);
}
/** Ctor from representation, for internal use only. */
matrix::matrix(unsigned r, unsigned c, const exvector & m2)
- : inherited(TINFO_matrix), row(r), col(c), m(m2)
+ : inherited(&matrix::tinfo_static), row(r), col(c), m(m2)
{
setflag(status_flags::not_shareable);
}
* If the list has more elements than the matrix, the excessive elements are
* thrown away. */
matrix::matrix(unsigned r, unsigned c, const lst & l)
- : inherited(TINFO_matrix), row(r), col(c), m(r*c, _ex0)
+ : inherited(&matrix::tinfo_static), row(r), col(c), m(r*c, _ex0)
{
setflag(status_flags::not_shareable);
if (!(n.find_unsigned("row", row)) || !(n.find_unsigned("col", col)))
throw (std::runtime_error("unknown matrix dimensions in archive"));
m.reserve(row * col);
- for (unsigned int i=0; true; i++) {
+ archive_node::archive_node_cit first = n.find_first("m");
+ archive_node::archive_node_cit last = n.find_last("m");
+ ++last;
+ for (archive_node::archive_node_cit i=first; i<last; ++i) {
ex e;
- if (n.find_ex("m", e, sym_lst, i))
- m.push_back(e);
- else
- break;
+ n.find_ex_by_loc(i, e, sym_lst);
+ m.push_back(e);
}
}
return *this;
}
+ex matrix::real_part() const
+{
+ exvector v;
+ v.reserve(m.size());
+ for (exvector::const_iterator i=m.begin(); i!=m.end(); ++i)
+ v.push_back(i->real_part());
+ return matrix(row, col, v);
+}
+
+ex matrix::imag_part() const
+{
+ exvector v;
+ v.reserve(m.size());
+ for (exvector::const_iterator i=m.begin(); i!=m.end(); ++i)
+ v.push_back(i->imag_part());
+ return matrix(row, col, v);
+}
+
// protected
int matrix::compare_same_type(const basic & other) const
for (unsigned r1=0; r1<this->rows(); ++r1) {
for (unsigned c=0; c<this->cols(); ++c) {
+ // Quick test: can we shortcut?
if (m[r1*col+c].is_zero())
continue;
for (unsigned r2=0; r2<other.cols(); ++r2)
- prod[r1*other.col+r2] += (m[r1*col+c] * other.m[c*other.col+r2]).expand();
+ prod[r1*other.col+r2] += (m[r1*col+c] * other.m[c*other.col+r2]);
}
}
return matrix(row, other.col, prod);
// 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);
unsigned sparse_count = 0; // counts non-zero elements
exvector::const_iterator r = m.begin(), rend = m.end();
while (r != rend) {
+ if (!r->info(info_flags::numeric))
+ numeric_flag = false;
exmap srl; // symbol replacement list
ex rtest = r->to_rational(srl);
if (!rtest.is_zero())
++sparse_count;
- if (!rtest.info(info_flags::numeric))
- numeric_flag = false;
if (!rtest.info(info_flags::crational_polynomial) &&
rtest.info(info_flags::rational_function))
normal_flag = true;
else
return m[0].expand();
}
-
+
// Compute the determinant
switch(algo) {
case determinant_algo::gauss: {
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();
* @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();
}
+/** 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
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();
}
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)
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) {
++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;
}
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)
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) {
++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;
}
}
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)
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,
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) {
++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();
return k;
}
+/** Function to check that all elements of the matrix are zero.
+ */
+bool matrix::is_zero_matrix() const
+{
+ for (exvector::const_iterator i=m.begin(); i!=m.end(); ++i)
+ if(!(i->is_zero()))
+ return false;
+ return true;
+}
+
ex lst_to_matrix(const lst & l)
{
lst::const_iterator itr, itc;
return M;
}
+ex reduced_matrix(const matrix& m, unsigned r, unsigned c)
+{
+ if (r+1>m.rows() || c+1>m.cols() || m.cols()<2 || m.rows()<2)
+ throw std::runtime_error("minor_matrix(): index out of bounds");
+
+ const unsigned rows = m.rows()-1;
+ const unsigned cols = m.cols()-1;
+ matrix &M = *new matrix(rows, cols);
+ M.setflag(status_flags::dynallocated | status_flags::evaluated);
+
+ unsigned ro = 0;
+ unsigned ro2 = 0;
+ while (ro2<rows) {
+ if (ro==r)
+ ++ro;
+ unsigned co = 0;
+ unsigned co2 = 0;
+ while (co2<cols) {
+ if (co==c)
+ ++co;
+ M(ro2,co2) = m(ro, co);
+ ++co;
+ ++co2;
+ }
+ ++ro;
+ ++ro2;
+ }
+
+ return M;
+}
+
+ex sub_matrix(const matrix&m, unsigned r, unsigned nr, unsigned c, unsigned nc)
+{
+ if (r+nr>m.rows() || c+nc>m.cols())
+ throw std::runtime_error("sub_matrix(): index out of bounds");
+
+ matrix &M = *new matrix(nr, nc);
+ M.setflag(status_flags::dynallocated | status_flags::evaluated);
+
+ for (unsigned ro=0; ro<nr; ++ro) {
+ for (unsigned co=0; co<nc; ++co) {
+ M(ro,co) = m(ro+r,co+c);
+ }
+ }
+
+ return M;
+}
+
} // namespace GiNaC