X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fmatrix.cpp;h=038084b6486e363ea38b02987fb02268793754dc;hp=a4d789a68132c17d3832b9ec355808ff56e33576;hb=c8292b5d0062c6455dd553fdc5d7141ea03547b1;hpb=da64e515abf7243bc4c84ca3631470931c4e6691

diff --git a/ginac/matrix.cpp b/ginac/matrix.cpp
index a4d789a6..038084b6 100644
--- a/ginac/matrix.cpp
+++ b/ginac/matrix.cpp
@@ -3,7 +3,7 @@
  *  Implementation of symbolic matrices */
 
 /*
- *  GiNaC Copyright (C) 1999-2005 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
@@ -53,7 +53,7 @@ GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(matrix, basic,
 //////////
 
 /** 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);
 }
@@ -69,7 +69,7 @@ matrix::matrix() : inherited(TINFO_matrix), row(1), col(1), m(1, _ex0)
  *  @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);
 }
@@ -78,7 +78,7 @@ matrix::matrix(unsigned r, unsigned c)
 
 /** 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);
 }
@@ -88,7 +88,7 @@ matrix::matrix(unsigned r, unsigned c, const exvector & m2)
  *  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);
 
@@ -113,12 +113,13 @@ matrix::matrix(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
 	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);
 	}
 }
 
@@ -262,6 +263,24 @@ ex matrix::conjugate() const
 	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
@@ -580,10 +599,11 @@ matrix matrix::mul(const matrix & 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);
@@ -647,12 +667,12 @@ 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);
@@ -730,12 +750,12 @@ ex matrix::determinant(unsigned algo) const
 	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;
@@ -1508,6 +1528,16 @@ int matrix::pivot(unsigned ro, unsigned co, bool symbolic)
 	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;
@@ -1598,4 +1628,52 @@ ex symbolic_matrix(unsigned r, unsigned c, const std::string & base_name, const
 	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