#include "relational.h"
#include "lst.h"
#include "numeric.h"
+#include "print.h"
#include "archive.h"
#include "utils.h"
#include "debugmsg.h"
return inherited::compare_same_type(other);
}
-DEFAULT_PRINT(tensdelta, "delta")
+DEFAULT_PRINT_LATEX(tensdelta, "delta", "\\delta")
DEFAULT_PRINT(tensmetric, "g")
-DEFAULT_PRINT(minkmetric, "eta")
-DEFAULT_PRINT(tensepsilon, "eps")
-
-ex tensor::subs(const lst & ls, const lst & lr) const
-{
- GINAC_ASSERT(ls.nops() == lr.nops());
-
- for (unsigned i=0; i<ls.nops(); i++) {
- if (is_ex_of_type(ls.op(i), tensor) &&
- compare_same_type(ex_to_tensor(ls.op(i)))==0)
- return lr.op(i);
- }
- return *this;
-}
+DEFAULT_PRINT_LATEX(minkmetric, "eta", "\\eta")
+DEFAULT_PRINT_LATEX(tensepsilon, "eps", "\\epsilon")
/** Automatic symbolic evaluation of an indexed delta tensor. */
ex tensdelta::eval_indexed(const basic & i) const
return indexed(tensepsilon(true, pos_sig), indexed::antisymmetric, i1, i2, i3, i4);
}
+ex eps0123(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 epsilon tensor must be of type varidx"));
+
+ ex dim = ex_to_idx(i1).get_dim();
+ if (dim.is_equal(4))
+ return lorentz_eps(i1, i2, i3, i4, pos_sig);
+ else
+ return indexed(tensepsilon(true, pos_sig), indexed::antisymmetric, i1, i2, i3, i4);
+}
+
} // namespace GiNaC