- simplify_indexed() simplifies c*(M).i.j -> (M').i.j (c: numeric, M: matrix)

[ginac.git] / ginac / matrix.cpp

diff --git a/ginac/matrix.cpp b/ginac/matrix.cpp
index f34534afdb1ab3ee39b567bd11c7ed7408010855..650799e55f6353db6807e1d42a8d7904cc55291b 100644 (file)
--- a/ginac/matrix.cpp
+++ b/ginac/matrix.cpp
@@ -95,6 +95,25 @@ matrix::matrix(unsigned r, unsigned c, const exvector & m2)
        debugmsg("matrix ctor from unsigned,unsigned,exvector",LOGLEVEL_CONSTRUCT);
 }
 
+/** Construct matrix from (flat) list of elements. If the list has fewer
+ *  elements than the matrix, the remaining matrix elements are set to zero.
+ *  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)
+{
+       debugmsg("matrix ctor from unsigned,unsigned,lst",LOGLEVEL_CONSTRUCT);
+       m.resize(r*c, _ex0());
+
+       for (unsigned i=0; i<l.nops(); i++) {
+               unsigned x = i % c;
+               unsigned y = i / c;
+               if (y >= r)
+                       break; // matrix smaller than list: throw away excessive elements
+               m[y*c+x] = l.op(i);
+       }
+}
+
 //////////
 // archiving
 //////////
@@ -385,6 +404,7 @@ ex matrix::eval_indexed(const basic & i) const
 ex matrix::add_indexed(const ex & self, const ex & other) const
 {
        GINAC_ASSERT(is_ex_of_type(self, indexed));
+       GINAC_ASSERT(is_ex_of_type(self.op(0), matrix));
        GINAC_ASSERT(is_ex_of_type(other, indexed));
        GINAC_ASSERT(self.nops() == 2 || self.nops() == 3);
 
@@ -416,6 +436,21 @@ ex matrix::add_indexed(const ex & self, const ex & other) const
        return self + other;
 }
 
+/** Product of an indexed matrix with a number. */
+ex matrix::scalar_mul_indexed(const ex & self, const numeric & other) const
+{
+       GINAC_ASSERT(is_ex_of_type(self, indexed));
+       GINAC_ASSERT(is_ex_of_type(self.op(0), matrix));
+       GINAC_ASSERT(self.nops() == 2 || self.nops() == 3);
+
+       const matrix &self_matrix = ex_to_matrix(self.op(0));
+
+       if (self.nops() == 2)
+               return indexed(self_matrix.mul(other), self.op(1));
+       else // self.nops() == 3
+               return indexed(self_matrix.mul(other), self.op(1), self.op(2));
+}
+
 /** Contraction of an indexed matrix with something else. */
 bool matrix::contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const
 {
@@ -581,6 +616,19 @@ matrix matrix::mul(const matrix & other) const
 }
 
 
+/** Product of matrix and scalar. */
+matrix matrix::mul(const numeric & other) const
+{
+       exvector prod(row * col);
+
+       for (unsigned r=0; r<row; ++r)
+               for (unsigned c=0; c<col; ++c)
+                       prod[r*col+c] = m[r*col+c] * other;
+
+       return matrix(row, col, prod);
+}
+
+
 /** operator() to access elements.
  *
  *  @param ro row of element
@@ -1392,12 +1440,8 @@ int matrix::pivot(unsigned ro, unsigned co, bool symbolic)
        return k;
 }
 
-/** Convert list of lists to matrix. */
-ex lst_to_matrix(const ex &l)
+ex lst_to_matrix(const lst & l)
 {
-       if (!is_ex_of_type(l, lst))
-               throw(std::invalid_argument("argument to lst_to_matrix() must be a lst"));
-       
        // Find number of rows and columns
        unsigned rows = l.nops(), cols = 0, i, j;
        for (i=0; i<rows; i++)
@@ -1415,4 +1459,15 @@ ex lst_to_matrix(const ex &l)
        return m;
 }
 
+ex diag_matrix(const lst & l)
+{
+       unsigned dim = l.nops();
+
+       matrix &m = *new matrix(dim, dim);
+       for (unsigned i=0; i<dim; i++)
+               m.set(i, i, l.op(i));
+
+       return m;
+}
+
 } // namespace GiNaC