* Implementation of GiNaC's special tensors. */
/*
- * GiNaC Copyright (C) 1999-2002 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 "indexed.h"
#include "symmetry.h"
#include "relational.h"
+#include "operators.h"
#include "lst.h"
#include "numeric.h"
#include "matrix.h"
-#include "print.h"
#include "archive.h"
#include "utils.h"
namespace GiNaC {
GINAC_IMPLEMENT_REGISTERED_CLASS(tensor, basic)
-GINAC_IMPLEMENT_REGISTERED_CLASS(tensdelta, tensor)
-GINAC_IMPLEMENT_REGISTERED_CLASS(tensmetric, tensor)
-GINAC_IMPLEMENT_REGISTERED_CLASS(minkmetric, tensmetric)
-GINAC_IMPLEMENT_REGISTERED_CLASS(spinmetric, tensmetric)
-GINAC_IMPLEMENT_REGISTERED_CLASS(tensepsilon, tensor)
+
+GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(tensdelta, tensor,
+ print_func<print_dflt>(&tensdelta::do_print).
+ print_func<print_latex>(&tensdelta::do_print_latex))
+
+GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(tensmetric, tensor,
+ print_func<print_dflt>(&tensmetric::do_print).
+ print_func<print_latex>(&tensmetric::do_print))
+
+GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(minkmetric, tensmetric,
+ print_func<print_dflt>(&minkmetric::do_print).
+ print_func<print_latex>(&minkmetric::do_print_latex))
+
+GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(spinmetric, tensmetric,
+ print_func<print_dflt>(&spinmetric::do_print).
+ print_func<print_latex>(&spinmetric::do_print_latex))
+
+GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(tensepsilon, tensor,
+ print_func<print_dflt>(&tensepsilon::do_print).
+ print_func<print_latex>(&tensepsilon::do_print_latex))
//////////
-// default ctor, dtor, copy ctor, assignment operator and helpers
+// constructors
//////////
-DEFAULT_CTORS(tensor)
-DEFAULT_CTORS(tensdelta)
-DEFAULT_CTORS(tensmetric)
-DEFAULT_COPY(spinmetric)
-DEFAULT_DESTROY(spinmetric)
-DEFAULT_DESTROY(minkmetric)
-DEFAULT_DESTROY(tensepsilon)
+tensor::tensor() : inherited(TINFO_tensor)
+{
+ setflag(status_flags::evaluated | status_flags::expanded);
+}
+
+DEFAULT_CTOR(tensdelta)
+DEFAULT_CTOR(tensmetric)
minkmetric::minkmetric() : pos_sig(false)
{
tinfo_key = TINFO_minkmetric;
}
-void minkmetric::copy(const minkmetric & other)
-{
- inherited::copy(other);
- pos_sig = other.pos_sig;
-}
-
tensepsilon::tensepsilon() : minkowski(false), pos_sig(false)
{
tinfo_key = TINFO_tensepsilon;
tinfo_key = TINFO_tensepsilon;
}
-void tensepsilon::copy(const tensepsilon & other)
-{
- inherited::copy(other);
- minkowski = other.minkowski;
- pos_sig = other.pos_sig;
-}
-
//////////
// archiving
//////////
DEFAULT_UNARCHIVE(minkmetric)
DEFAULT_UNARCHIVE(tensepsilon)
-minkmetric::minkmetric(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
+minkmetric::minkmetric(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
{
n.find_bool("pos_sig", pos_sig);
}
n.add_bool("pos_sig", pos_sig);
}
-tensepsilon::tensepsilon(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
+tensepsilon::tensepsilon(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
{
n.find_bool("minkowski", minkowski);
n.find_bool("pos_sig", pos_sig);
const idx & i1 = ex_to<idx>(i.op(1));
const idx & i2 = ex_to<idx>(i.op(2));
+ // The dimension of the indices must be equal, otherwise we use the minimal
+ // dimension
+ if (!i1.get_dim().is_equal(i2.get_dim())) {
+ ex min_dim = i1.minimal_dim(i2);
+ exmap m;
+ m[i1] = i1.replace_dim(min_dim);
+ m[i2] = i2.replace_dim(min_dim);
+ return i.subs(m, subs_options::no_pattern);
+ }
+
// Trace of delta tensor is the (effective) dimension of the space
if (is_dummy_pair(i1, i2)) {
try {
const varidx & i1 = ex_to<varidx>(i.op(1));
const varidx & i2 = ex_to<varidx>(i.op(2));
+ // The dimension of the indices must be equal, otherwise we use the minimal
+ // dimension
+ if (!i1.get_dim().is_equal(i2.get_dim())) {
+ ex min_dim = i1.minimal_dim(i2);
+ exmap m;
+ m[i1] = i1.replace_dim(min_dim);
+ m[i2] = i2.replace_dim(min_dim);
+ return i.subs(m, subs_options::no_pattern);
+ }
+
// A metric tensor with one covariant and one contravariant index gets
// replaced by a delta tensor
if (i1.is_covariant() != i2.is_covariant())
// 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++)
+ for (size_t 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.begin(), v.end());
// In a Minkowski space, check for covariant indices
if (minkowski) {
- for (unsigned j=1; j<i.nops(); j++) {
+ for (size_t j=1; j<i.nops(); j++) {
const ex & x = i.op(j);
- if (!is_ex_of_type(x, varidx))
+ if (!is_a<varidx>(x))
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())
again:
if (self_idx->is_symbolic()) {
- for (unsigned i=1; i<other->nops(); i++) {
+ for (size_t i=1; i<other->nops(); i++) {
const idx &other_idx = ex_to<idx>(other->op(i));
if (is_dummy_pair(*self_idx, other_idx)) {
try {
// minimal_dim() throws an exception when index dimensions are not comparable
ex min_dim = self_idx->minimal_dim(other_idx);
- *self = _ex1;
*other = other->subs(other_idx == free_idx->replace_dim(min_dim));
+ *self = _ex1; // *other is assigned first because assigning *self invalidates free_idx
return true;
} catch (std::exception &e) {
return false;
// If contracting with the delta tensor, let the delta do it
// (don't raise/lower delta indices)
- if (is_ex_of_type(other->op(0), tensdelta))
+ if (is_a<tensdelta>(other->op(0)))
return false;
// Replace the dummy index with this tensor's other index and remove
- // the tensor (this is valid for contractions with all other tensors)
+ // the tensor
return replace_contr_index(self, other);
}
GINAC_ASSERT(is_a<spinmetric>(self->op(0)));
// Contractions between spinor metrics
- if (is_ex_of_type(other->op(0), spinmetric)) {
+ if (is_a<spinmetric>(other->op(0))) {
const idx &self_i1 = ex_to<idx>(self->op(1));
const idx &self_i2 = ex_to<idx>(self->op(2));
const idx &other_i1 = ex_to<idx>(other->op(1));
// If contracting with the delta tensor, let the delta do it
// (don't raise/lower delta indices)
- if (is_ex_of_type(other->op(0), tensdelta))
+ if (is_a<tensdelta>(other->op(0)))
return false;
// Try to contract first index
again:
if (self_idx->is_symbolic()) {
- for (unsigned i=1; i<other->nops(); i++) {
+ for (size_t i=1; i<other->nops(); i++) {
const idx &other_idx = ex_to<idx>(other->op(i));
if (is_dummy_pair(*self_idx, other_idx)) {
// Contraction found, remove metric tensor and substitute
- // index in second object
- *self = (static_cast<const spinidx *>(self_idx)->is_covariant() ? sign : -sign);
+ // index in second object (assign *self last because this
+ // invalidates free_idx)
*other = other->subs(other_idx == *free_idx);
+ *self = (static_cast<const spinidx *>(self_idx)->is_covariant() ? sign : -sign);
return true;
}
}
GINAC_ASSERT(is_a<indexed>(*self));
GINAC_ASSERT(is_a<indexed>(*other));
GINAC_ASSERT(is_a<tensepsilon>(self->op(0)));
- unsigned num = self->nops() - 1;
+ size_t num = self->nops() - 1;
- if (is_ex_exactly_of_type(other->op(0), tensepsilon) && num+1 == other->nops()) {
+ if (is_exactly_a<tensepsilon>(other->op(0)) && num+1 == other->nops()) {
// Contraction of two epsilon tensors is a determinant
- ex dim = ex_to<idx>(self->op(1)).get_dim();
+ bool variance = is_a<varidx>(self->op(1));
matrix M(num, num);
- for (int i=0; i<num; i++) {
- for (int j=0; j<num; j++) {
+ for (size_t i=0; i<num; i++) {
+ for (size_t j=0; j<num; j++) {
if (minkowski)
M(i, j) = lorentz_g(self->op(i+1), other->op(j+1), pos_sig);
- else
+ else if (variance)
M(i, j) = metric_tensor(self->op(i+1), other->op(j+1));
+ else
+ M(i, j) = delta_tensor(self->op(i+1), other->op(j+1));
}
}
int sign = minkowski ? -1 : 1;
ex delta_tensor(const ex & i1, const ex & i2)
{
- if (!is_ex_of_type(i1, idx) || !is_ex_of_type(i2, idx))
+ if (!is_a<idx>(i1) || !is_a<idx>(i2))
throw(std::invalid_argument("indices of delta tensor must be of type idx"));
return indexed(tensdelta(), sy_symm(), i1, i2);
ex metric_tensor(const ex & i1, const ex & i2)
{
- if (!is_ex_of_type(i1, varidx) || !is_ex_of_type(i2, varidx))
+ if (!is_a<varidx>(i1) || !is_a<varidx>(i2))
throw(std::invalid_argument("indices of metric tensor must be of type varidx"));
- 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 metric tensor must have the same dimension"));
return indexed(tensmetric(), sy_symm(), i1, i2);
}
ex lorentz_g(const ex & i1, const ex & i2, bool pos_sig)
{
- if (!is_ex_of_type(i1, varidx) || !is_ex_of_type(i2, varidx))
+ if (!is_a<varidx>(i1) || !is_a<varidx>(i2))
throw(std::invalid_argument("indices of metric tensor must be of type varidx"));
- 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 metric tensor must have the same dimension"));
return indexed(minkmetric(pos_sig), sy_symm(), i1, i2);
}
ex spinor_metric(const ex & i1, const ex & i2)
{
- if (!is_ex_of_type(i1, spinidx) || !is_ex_of_type(i2, spinidx))
+ if (!is_a<spinidx>(i1) || !is_a<spinidx>(i2))
throw(std::invalid_argument("indices of spinor metric must be of type spinidx"));
if (!ex_to<idx>(i1).get_dim().is_equal(2) || !ex_to<idx>(i2).get_dim().is_equal(2))
throw(std::runtime_error("index dimension for spinor metric must be 2"));
ex epsilon_tensor(const ex & i1, const ex & i2)
{
- if (!is_ex_of_type(i1, idx) || !is_ex_of_type(i2, idx))
+ if (!is_a<idx>(i1) || !is_a<idx>(i2))
throw(std::invalid_argument("indices of epsilon tensor must be of type idx"));
ex dim = ex_to<idx>(i1).get_dim();
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))
+ if (!is_a<idx>(i1) || !is_a<idx>(i2) || !is_a<idx>(i3))
throw(std::invalid_argument("indices of epsilon tensor must be of type idx"));
ex dim = ex_to<idx>(i1).get_dim();
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))
+ if (!is_a<varidx>(i1) || !is_a<varidx>(i2) || !is_a<varidx>(i3) || !is_a<varidx>(i4))
throw(std::invalid_argument("indices of Lorentz epsilon tensor must be of type varidx"));
ex dim = ex_to<idx>(i1).get_dim();
git://www.ginac.de / ginac.git / blobdiff