- clifford::metric stores the metric without indices, removing rendundancy

- default metric comes from a flyweight to conserve memory
- API change: The 'metr' argument to clifford_unit() and lst_to_clifford()
  is now a tensor or a symmetric matrix without indices

diff --git a/ginac/clifford.cpp b/ginac/clifford.cpp
index afc9989486bdee52218eac467e7eec32f6893329..ba5d33986a17eb3755a2c72aec33f24ac6429504 100644 (file)
--- a/ginac/clifford.cpp
+++ b/ginac/clifford.cpp
@@ -72,7 +72,13 @@ GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(diracgammaR, tensor,
 // default constructors
 //////////
 
 // default constructors
 //////////
 

-clifford::clifford() : representation_label(0), metric(lorentz_g(varidx((new symbol)->setflag(status_flags::dynallocated), 4), varidx((new symbol)->setflag(status_flags::dynallocated), 4)))
+static ex default_metric()
+{
+       static ex m = (new minkmetric)->setflag(status_flags::dynallocated);
+       return m;
+}
+
+clifford::clifford() : representation_label(0), metric(default_metric())

 {
        tinfo_key = TINFO_clifford;
 }
 {
        tinfo_key = TINFO_clifford;
 }


@@ -149,17 +155,15 @@ DEFAULT_ARCHIVING(diracgammaR)
 
 ex clifford::get_metric(const ex & i, const ex & j) const
 {
 
 ex clifford::get_metric(const ex & i, const ex & j) const
 {

-       return metric.subs(metric.op(1) == i).subs(metric.op(2) == j);
+       return indexed(metric, symmetric2(), i, j);

 }
 
 bool clifford::same_metric(const ex & other) const
 {
        if (is_a<clifford>(other)) {
 }
 
 bool clifford::same_metric(const ex & other) const
 {
        if (is_a<clifford>(other)) {

-               ex m = get_metric();
-               return m.is_equal(ex_to<clifford>(other).get_metric(m.op(1), m.op(2)));
+               return get_metric().is_equal(ex_to<clifford>(other).get_metric());

        } else if (is_a<indexed>(other)) {
        } else if (is_a<indexed>(other)) {

-               ex m = get_metric(other.op(1), other.op(2));
-               return m.is_equal(other);
+               return get_metric(other.op(1), other.op(2)).is_equal(other);

        } else
                return false;
 }
        } else
                return false;
 }


@@ -371,7 +375,7 @@ bool cliffordunit::contract_with(exvector::iterator self, exvector::iterator oth
                // Find if a previous contraction produces the square of self
                int prev_square = find_same_metric(v, self[0]);
                varidx d((new symbol)->setflag(status_flags::dynallocated), ex_to<idx>(ex_to<idx>(self->op(1)).get_dim()));
                // Find if a previous contraction produces the square of self
                int prev_square = find_same_metric(v, self[0]);
                varidx d((new symbol)->setflag(status_flags::dynallocated), ex_to<idx>(ex_to<idx>(self->op(1)).get_dim()));

-               ex squared_metric = unit.get_metric(self->op(1), d)*unit.get_metric(d.toggle_variance(), other->op(1));
+               ex squared_metric = unit.get_metric(self->op(1), d) * unit.get_metric(d.toggle_variance(), other->op(1));

 
                // e~mu e.mu = Tr ONE
                if (other - self == 1) {
 
                // e~mu e.mu = Tr ONE
                if (other - self == 1) {


@@ -389,7 +393,7 @@ bool cliffordunit::contract_with(exvector::iterator self, exvector::iterator oth
 
                        const ex & ia = self[1].op(1);
                        const ex & ib = self[1].op(1);
 
                        const ex & ia = self[1].op(1);
                        const ex & ib = self[1].op(1);

-                       if (is_a<tensmetric>(unit.get_metric().op(0)))
+                       if (is_a<tensmetric>(unit.get_metric()))

                                *self = 2 - unit.get_metric(self->op(1), other->op(1));
                        else if (prev_square != 0) {
                                *self = 2-squared_metric;
                                *self = 2 - unit.get_metric(self->op(1), other->op(1));
                        else if (prev_square != 0) {
                                *self = 2-squared_metric;


@@ -419,7 +423,7 @@ bool cliffordunit::contract_with(exvector::iterator self, exvector::iterator oth
 
                        const ex & ia = next_to_last->op(1);
                        const ex & ib = next_to_last->op(1);
 
                        const ex & ia = next_to_last->op(1);
                        const ex & ib = next_to_last->op(1);

-                       if (is_a<tensmetric>(unit.get_metric().op(0)))
+                       if (is_a<tensmetric>(unit.get_metric()))

                                *self = 2 * (*next_to_last) * S - (*self) * S * (*other) * (*next_to_last);
                        else if (prev_square != 0) {
                                *self = 2 * (*next_to_last) * S  - (*self) * S * (*other) * (*next_to_last)*unit.get_metric(self->op(1),self->op(1));
                                *self = 2 * (*next_to_last) * S - (*self) * S * (*other) * (*next_to_last);
                        else if (prev_square != 0) {
                                *self = 2 * (*next_to_last) * S  - (*self) * S * (*other) * (*next_to_last)*unit.get_metric(self->op(1),self->op(1));


@@ -546,7 +550,7 @@ ex clifford::eval_ncmul(const exvector & v) const
                                const ex & ia = a.op(1);
                                const ex & ib = b.op(1);
                                if (ia.is_equal(ib)) { // gamma~alpha gamma~alpha -> g~alpha~alpha
                                const ex & ia = a.op(1);
                                const ex & ib = b.op(1);
                                if (ia.is_equal(ib)) { // gamma~alpha gamma~alpha -> g~alpha~alpha

-                                       a = ex_to<clifford>(a).get_metric(ia,ib);
+                                       a = ex_to<clifford>(a).get_metric(ia, ib);

                                        b = dirac_ONE(representation_label);
                                        something_changed = true;
                                }
                                        b = dirac_ONE(representation_label);
                                        something_changed = true;
                                }


@@ -640,17 +644,12 @@ ex dirac_ONE(unsigned char rl)
 
 ex clifford_unit(const ex & mu, const ex & metr, unsigned char rl)
 {
 
 ex clifford_unit(const ex & mu, const ex & metr, unsigned char rl)
 {

+       static ex unit = (new cliffordunit)->setflag(status_flags::dynallocated);
+

        if (!is_a<varidx>(mu))
                throw(std::invalid_argument("index of Clifford unit must be of type varidx"));
        if (!is_a<varidx>(mu))
                throw(std::invalid_argument("index of Clifford unit must be of type varidx"));

-       if (!is_a<indexed>(metr))
-               throw(std::invalid_argument("metric for Clifford unit must be of type indexed"));
-       exvector d = ex_to<indexed>(metr).get_indices();
-       if (d.size() > 2 || ex_to<idx>(d[0]).get_dim() != ex_to<idx>(d[1]).get_dim())
-         //|| ex_to<idx>(d[0]).get_dim() != ex_to<idx>(mu).get_dim())
-               throw(std::invalid_argument("metric is not square"));
-       else
-               ex_to<idx>(mu).replace_dim(ex_to<idx>(d[0]).get_dim());
-       return clifford(cliffordunit(), mu, metr, rl);
+
+       return clifford(unit, mu, metr, rl);

 }
 
 ex dirac_gamma(const ex & mu, unsigned char rl)
 }
 
 ex dirac_gamma(const ex & mu, unsigned char rl)


@@ -660,8 +659,7 @@ ex dirac_gamma(const ex & mu, unsigned char rl)
        if (!is_a<varidx>(mu))
                throw(std::invalid_argument("index of Dirac gamma must be of type varidx"));
 
        if (!is_a<varidx>(mu))
                throw(std::invalid_argument("index of Dirac gamma must be of type varidx"));
 

-       ex dim = ex_to<idx>(mu).get_dim();
-       return clifford(gamma, mu, lorentz_g(varidx((new symbol)->setflag(status_flags::dynallocated), dim),varidx((new symbol)->setflag(status_flags::dynallocated), dim)), rl);
+       return clifford(gamma, mu, default_metric(), rl);

 }
 
 ex dirac_gamma5(unsigned char rl)
 }
 
 ex dirac_gamma5(unsigned char rl)

diff --git a/ginac/clifford.h b/ginac/clifford.h
index d3109a0cba61cbb7c3211775bd90ef5d08d76cd5..f6a9820b6e9f08bfa5a1d6b21abf096d6f5da258 100644 (file)
--- a/ginac/clifford.h
+++ b/ginac/clifford.h
@@ -189,7 +189,7 @@ ex dirac_ONE(unsigned char rl = 0);
 /** Create a Clifford unit object.
  *
  *  @param mu Index (must be of class varidx or a derived class)
 /** Create a Clifford unit object.
  *
  *  @param mu Index (must be of class varidx or a derived class)

- *  @param metr Metric (must be of class tensor or a derived class)
+ *  @param metr Metric (should be of class tensmetric or a derived class, or a symmetric matrix)

  *  @param rl Representation label
  *  @return newly constructed Clifford unit object */
 ex clifford_unit(const ex & mu, const ex & metr, unsigned char rl = 0);
  *  @param rl Representation label
  *  @return newly constructed Clifford unit object */
 ex clifford_unit(const ex & mu, const ex & metr, unsigned char rl = 0);


@@ -265,7 +265,7 @@ ex clifford_inverse(const ex & e);
  *
  *  @param v List or vector of coordinates
  *  @param mu Index (must be of class varidx or a derived class)
  *
  *  @param v List or vector of coordinates
  *  @param mu Index (must be of class varidx or a derived class)

- *  @param metr Metric (must be of class tensor or a derived class)
+ *  @param metr Metric (should be of class tensmetric or a derived class, or a symmetric matrix)

  *  @param rl Representation label
  *  @return Clifford vector with given components */
 ex lst_to_clifford(const ex & v, const ex & mu,  const ex & metr, unsigned char rl = 0);
  *  @param rl Representation label
  *  @return Clifford vector with given components */
 ex lst_to_clifford(const ex & v, const ex & mu,  const ex & metr, unsigned char rl = 0);