* Implementation of GiNaC's indices. */
/*
- * GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2003 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
*/
#include <iostream>
+#include <sstream>
#include <stdexcept>
#include "idx.h"
#include "symbol.h"
#include "lst.h"
+#include "relational.h"
#include "print.h"
#include "archive.h"
#include "utils.h"
} else {
if (is_a<print_latex>(c))
- c.s << "_{";
+ c.s << "{";
else
c.s << ".";
- bool need_parens = !(is_ex_exactly_of_type(value, numeric) || is_ex_of_type(value, symbol));
+ bool need_parens = !(is_exactly_a<numeric>(value) || is_a<symbol>(value));
if (need_parens)
c.s << "(";
value.print(c);
dim.print(c, level + delta_indent);
} else {
- if (is_a<print_latex>(c)) {
- if (covariant)
- c.s << "_{";
- else
- c.s << "^{";
- } else {
+ if (is_a<print_latex>(c))
+ c.s << "{";
+ else {
if (covariant)
c.s << ".";
else
c.s << "~";
}
- bool need_parens = !(is_ex_exactly_of_type(value, numeric) || is_ex_of_type(value, symbol));
+ bool need_parens = !(is_exactly_a<numeric>(value) || is_a<symbol>(value));
if (need_parens)
c.s << "(";
value.print(c);
else
c.s << "*";
}
- bool need_parens = !(is_ex_exactly_of_type(value, numeric) || is_ex_of_type(value, symbol));
+ bool need_parens = !(is_exactly_a<numeric>(value) || is_a<symbol>(value));
if (need_parens)
c.s << "(";
value.print(c);
if (is_equal(ex_to<basic>(ls.op(i)))) {
// Substitution index->index
- if (is_ex_of_type(lr.op(i), idx))
+ if (is_a<idx>(lr.op(i)))
return lr.op(i);
// Otherwise substitute value
{
const idx &o = static_cast<const idx &>(other);
- // Only pure symbols form dummy pairs, "2n+1" doesn't
- if (!is_ex_of_type(value, symbol))
+ // Only pure symbols form dummy pairs, numeric indices and expressions
+ // like "2n+1" don't
+ if (!is_a<symbol>(value))
return false;
// Value must be equal, of course
if (!value.is_equal(o.value))
return false;
- // Also the dimension
- return dim.is_equal(o.dim);
+ // Dimensions need not be equal but must be comparable (so we can
+ // determine the minimum dimension of contractions)
+ if (dim.is_equal(o.dim))
+ return true;
+
+ return (dim < o.dim || dim > o.dim || (is_exactly_a<numeric>(dim) && is_a<symbol>(o.dim)) || (is_a<symbol>(dim) && is_exactly_a<numeric>(o.dim)));
}
bool varidx::is_dummy_pair_same_type(const basic & other) const
// non-virtual functions
//////////
+ex idx::replace_dim(const ex & new_dim) const
+{
+ idx *i_copy = static_cast<idx *>(duplicate());
+ i_copy->dim = new_dim;
+ i_copy->clearflag(status_flags::hash_calculated);
+ return i_copy->setflag(status_flags::dynallocated);
+}
+
+ex idx::minimal_dim(const idx & other) const
+{
+ return GiNaC::minimal_dim(dim, other.dim);
+}
+
ex varidx::toggle_variance(void) const
{
varidx *i_copy = static_cast<varidx *>(duplicate());
bool is_dummy_pair(const ex & e1, const ex & e2)
{
// The expressions must be indices
- if (!is_ex_of_type(e1, idx) || !is_ex_of_type(e2, idx))
+ if (!is_a<idx>(e1) || !is_a<idx>(e2))
return false;
return is_dummy_pair(ex_to<idx>(e1), ex_to<idx>(e2));
out_free.push_back(*last);
}
+ex minimal_dim(const ex & dim1, const ex & dim2)
+{
+ if (dim1.is_equal(dim2) || dim1 < dim2 || (is_exactly_a<numeric>(dim1) && is_a<symbol>(dim2)))
+ return dim1;
+ else if (dim1 > dim2 || (is_a<symbol>(dim1) && is_exactly_a<numeric>(dim2)))
+ return dim2;
+ else {
+ std::ostringstream s;
+ s << "minimal_dim(): index dimensions " << dim1 << " and " << dim2 << " cannot be ordered";
+ throw (std::runtime_error(s.str()));
+ }
+}
+
} // namespace GiNaC