*/
#include <stdexcept>
+#include <vector>
#include "tensor.h"
#include "idx.h"
// default constructor, destructor, copy constructor assignment operator and helpers
//////////
-#define DEFAULT_CTORS(classname) \
-classname::classname() : inherited(TINFO_##classname) \
-{ \
- debugmsg(#classname " default constructor", LOGLEVEL_CONSTRUCT); \
-} \
-void classname::copy(const classname & other) \
-{ \
- inherited::copy(other); \
-} \
-void classname::destroy(bool call_parent) \
-{ \
- if (call_parent) \
- inherited::destroy(call_parent); \
-}
-
tensor::tensor(unsigned ti) : inherited(ti)
{
debugmsg("tensor constructor from unsigned", LOGLEVEL_CONSTRUCT); \
DEFAULT_CTORS(tensor)
DEFAULT_CTORS(tensdelta)
DEFAULT_CTORS(tensmetric)
-DEFAULT_CTORS(tensepsilon)
+DEFAULT_DESTROY(minkmetric)
+DEFAULT_DESTROY(tensepsilon)
minkmetric::minkmetric() : pos_sig(false)
{
pos_sig = other.pos_sig;
}
-void minkmetric::destroy(bool call_parent)
+tensepsilon::tensepsilon() : minkowski(false), pos_sig(false)
+{
+ debugmsg("tensepsilon default constructor", LOGLEVEL_CONSTRUCT);
+ tinfo_key = TINFO_tensepsilon;
+}
+
+tensepsilon::tensepsilon(bool mink, bool ps) : minkowski(mink), pos_sig(ps)
{
- if (call_parent)
- inherited::destroy(call_parent);
+ debugmsg("tensepsilon constructor from bool,bool", LOGLEVEL_CONSTRUCT);
+ tinfo_key = TINFO_tensepsilon;
+}
+
+void tensepsilon::copy(const tensepsilon & other)
+{
+ inherited::copy(other);
+ minkowski = other.minkowski;
+ pos_sig = other.pos_sig;
}
//////////
// archiving
//////////
-#define DEFAULT_ARCHIVING(classname) \
-classname::classname(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst) \
-{ \
- debugmsg(#classname " constructor from archive_node", LOGLEVEL_CONSTRUCT); \
-} \
-ex classname::unarchive(const archive_node &n, const lst &sym_lst) \
-{ \
- return (new classname(n, sym_lst))->setflag(status_flags::dynallocated); \
-} \
-void classname::archive(archive_node &n) const \
-{ \
- inherited::archive(n); \
-}
-
DEFAULT_ARCHIVING(tensor)
DEFAULT_ARCHIVING(tensdelta)
DEFAULT_ARCHIVING(tensmetric)
-DEFAULT_ARCHIVING(tensepsilon)
+DEFAULT_UNARCHIVE(minkmetric)
+DEFAULT_UNARCHIVE(tensepsilon)
minkmetric::minkmetric(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
{
n.find_bool("pos_sig", pos_sig);
}
-ex minkmetric::unarchive(const archive_node &n, const lst &sym_lst)
+void minkmetric::archive(archive_node &n) const
+{
+ inherited::archive(n);
+ n.add_bool("pos_sig", pos_sig);
+}
+
+tensepsilon::tensepsilon(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
{
- return (new minkmetric(n, sym_lst))->setflag(status_flags::dynallocated);
+ debugmsg("tensepsilon constructor from archive_node", LOGLEVEL_CONSTRUCT);
+ n.find_bool("minkowski", minkowski);
+ n.find_bool("pos_sig", pos_sig);
}
-void minkmetric::archive(archive_node &n) const
+void tensepsilon::archive(archive_node &n) const
{
inherited::archive(n);
+ n.add_bool("minkowski", minkowski);
n.add_bool("pos_sig", pos_sig);
}
// functions overriding virtual functions from bases classes
//////////
-#define DEFAULT_COMPARE(classname) \
-int classname::compare_same_type(const basic & other) const \
-{ \
- /* by default, two tensors of the same class are always identical */ \
- return 0; \
-}
-
DEFAULT_COMPARE(tensor)
DEFAULT_COMPARE(tensdelta)
DEFAULT_COMPARE(tensmetric)
-DEFAULT_COMPARE(tensepsilon)
int minkmetric::compare_same_type(const basic & other) const
{
return inherited::compare_same_type(other);
}
-void tensdelta::print(std::ostream & os, unsigned upper_precedence) const
+int tensepsilon::compare_same_type(const basic & other) const
{
- debugmsg("tensdelta print",LOGLEVEL_PRINT);
- os << "delta";
-}
+ GINAC_ASSERT(is_of_type(other, tensepsilon));
+ const tensepsilon &o = static_cast<const tensepsilon &>(other);
-void tensmetric::print(std::ostream & os, unsigned upper_precedence) const
-{
- debugmsg("tensmetric print",LOGLEVEL_PRINT);
- os << "g";
-}
-
-void minkmetric::print(std::ostream & os, unsigned upper_precedence) const
-{
- debugmsg("minkmetric print",LOGLEVEL_PRINT);
- os << "eta";
+ if (minkowski != o.minkowski)
+ return minkowski ? -1 : 1;
+ else if (pos_sig != o.pos_sig)
+ return pos_sig ? -1 : 1;
+ else
+ return inherited::compare_same_type(other);
}
-void tensepsilon::print(std::ostream & os, unsigned upper_precedence) const
-{
- debugmsg("tensepsilon print",LOGLEVEL_PRINT);
- os << "eps";
-}
+DEFAULT_PRINT(tensdelta, "delta")
+DEFAULT_PRINT(tensmetric, "g")
+DEFAULT_PRINT(minkmetric, "eta")
+DEFAULT_PRINT(tensepsilon, "eps")
/** Automatic symbolic evaluation of an indexed delta tensor. */
ex tensdelta::eval_indexed(const basic & i) const
return inherited::eval_indexed(i);
}
+/** Automatic symbolic evaluation of an indexed epsilon tensor. */
+ex tensepsilon::eval_indexed(const basic & i) const
+{
+ GINAC_ASSERT(is_of_type(i, indexed));
+ GINAC_ASSERT(i.nops() > 1);
+ GINAC_ASSERT(is_ex_of_type(i.op(0), tensepsilon));
+
+ // Convolutions are zero
+ if (static_cast<const indexed &>(i).get_dummy_indices().size() != 0)
+ return _ex0();
+
+ // Numeric evaluation
+ if (static_cast<const indexed &>(i).all_index_values_are(info_flags::nonnegint)) {
+
+ // Get sign of index permutation (the indices should already be in
+ // a canonic order but we can't assume what exactly that order is)
+ std::vector<int> v;
+ v.reserve(i.nops() - 1);
+ for (unsigned j=1; j<i.nops(); j++)
+ v.push_back(ex_to_numeric(ex_to_idx(i.op(j)).get_value()).to_int());
+ int sign = permutation_sign(v);
+
+ // In a Minkowski space, check for covariant indices
+ if (minkowski) {
+ for (unsigned j=1; j<i.nops(); j++) {
+ const ex & x = i.op(j);
+ if (!is_ex_of_type(x, varidx))
+ throw(std::runtime_error("indices of epsilon tensor in Minkowski space must be of type varidx"));
+ if (ex_to_varidx(x).is_covariant())
+ if (ex_to_idx(x).get_value().is_zero())
+ sign = (pos_sig ? -sign : sign);
+ else
+ sign = (pos_sig ? sign : -sign);
+ }
+ }
+
+ return sign;
+ }
+
+ // No further simplifications
+ return i.hold();
+}
+
/** Contraction of an indexed delta tensor with something else. */
bool tensdelta::contract_with(exvector::iterator self, exvector::iterator other, exvector & v) const
{
if (!is_ex_of_type(i1, varidx) || !is_ex_of_type(i2, varidx))
throw(std::invalid_argument("indices of metric tensor must be of type varidx"));
- return indexed(tensmetric(), i1, i2);
+ return indexed(tensmetric(), indexed::symmetric, i1, i2);
}
ex lorentz_g(const ex & i1, const ex & i2, bool pos_sig)
{
if (!is_ex_of_type(i1, idx) || !is_ex_of_type(i2, idx))
throw(std::invalid_argument("indices of epsilon tensor must be of type idx"));
- if (!ex_to_idx(i1).get_dim().is_equal(_ex2()) || !ex_to_idx(i2).get_dim().is_equal(_ex2()))
- throw(std::invalid_argument("index dimension of epsilon tensor must match number of indices"));
+
+ ex dim = ex_to_idx(i1).get_dim();
+ if (!dim.is_equal(ex_to_idx(i2).get_dim()))
+ throw(std::invalid_argument("all indices of epsilon tensor must have the same dimension"));
+ if (!ex_to_idx(i1).get_dim().is_equal(_ex2()))
+ throw(std::runtime_error("index dimension of epsilon tensor must match number of indices"));
return indexed(tensepsilon(), indexed::antisymmetric, i1, i2);
}
+ex epsilon_tensor(const ex & i1, const ex & i2, const ex & i3)
+{
+ if (!is_ex_of_type(i1, idx) || !is_ex_of_type(i2, idx) || !is_ex_of_type(i3, idx))
+ throw(std::invalid_argument("indices of epsilon tensor must be of type idx"));
+
+ ex dim = ex_to_idx(i1).get_dim();
+ if (!dim.is_equal(ex_to_idx(i2).get_dim()) || !dim.is_equal(ex_to_idx(i3).get_dim()))
+ throw(std::invalid_argument("all indices of epsilon tensor must have the same dimension"));
+ if (!ex_to_idx(i1).get_dim().is_equal(_ex3()))
+ throw(std::runtime_error("index dimension of epsilon tensor must match number of indices"));
+
+ return indexed(tensepsilon(), indexed::antisymmetric, i1, i2, i3);
+}
+
+ex lorentz_eps(const ex & i1, const ex & i2, const ex & i3, const ex & i4, bool pos_sig)
+{
+ if (!is_ex_of_type(i1, varidx) || !is_ex_of_type(i2, varidx) || !is_ex_of_type(i3, varidx) || !is_ex_of_type(i4, varidx))
+ throw(std::invalid_argument("indices of Lorentz epsilon tensor must be of type varidx"));
+
+ ex dim = ex_to_idx(i1).get_dim();
+ if (!dim.is_equal(ex_to_idx(i2).get_dim()) || !dim.is_equal(ex_to_idx(i3).get_dim()) || !dim.is_equal(ex_to_idx(i4).get_dim()))
+ throw(std::invalid_argument("all indices of epsilon tensor must have the same dimension"));
+ if (!ex_to_idx(i1).get_dim().is_equal(_ex4()))
+ throw(std::runtime_error("index dimension of epsilon tensor must match number of indices"));
+
+ return indexed(tensepsilon(true, pos_sig), indexed::antisymmetric, i1, i2, i3, i4);
+}
+
} // namespace GiNaC
git://www.ginac.de / ginac.git / blobdiff