bool isSymbolicSparse(const SXMatrix& ex) {
for(int k=0; k<ex.size(); ++k) // loop over non-zero elements
if(!ex.at(k)->isSymbolic()) // if an element is not symbolic
return false;
return true;
}
void substituteInPlace(const SXMatrix &v, SXMatrix &vdef, std::vector<SXMatrix>& ex, bool reverse){
casadi_assert_message(isSymbolic(v),"the variable is not symbolic");
casadi_assert_message(v.sparsity() == vdef.sparsity(),"the sparsity patterns of the expression and its defining expression do not match");
if(v.empty()) return; // quick return if nothing to replace
// Function inputs
std::vector<SXMatrix> f_in;
if(!reverse) f_in.push_back(v);
// Function outputs
std::vector<SXMatrix> f_out;
f_out.push_back(vdef);
f_out.insert(f_out.end(),ex.begin(),ex.end());
// Write the mapping function
SXFunction f(f_in,f_out);
f.init();
// Get references to the internal data structures
const vector<SXAlgEl>& algorithm = f.algorithm();
vector<SX> work(f.getWorkSize());
// Iterator to the binary operations
vector<SX>::const_iterator b_it=f->operations_.begin();
// Iterator to stack of constants
vector<SX>::const_iterator c_it = f->constants_.begin();
// Iterator to free variables
vector<SX>::const_iterator p_it = f->free_vars_.begin();
// Evaluate the algorithm
for(vector<SXAlgEl>::const_iterator it=algorithm.begin(); it<algorithm.end(); ++it){
switch(it->op){
case OP_INPUT:
// reverse is false, substitute out
work[it->res] = vdef.at(it->arg.i[1]);
break;
case OP_OUTPUT:
if(it->res==0){
vdef.at(it->arg.i[1]) = work[it->arg.i[0]];
if(reverse){
// Use the new variable henceforth, substitute in
work[it->arg.i[0]] = v.at(it->arg.i[1]);
}
} else {
// Auxillary output
ex[it->res-1].at(it->arg.i[1]) = work[it->arg.i[0]];
}
break;
case OP_CONST: work[it->res] = *c_it++; break;
case OP_PARAMETER: work[it->res] = *p_it++; break;
default:
{
switch(it->op){
CASADI_MATH_FUN_BUILTIN(work[it->arg.i[0]],work[it->arg.i[1]],work[it->res])
}
// Avoid creating duplicates
const int depth = 2; // NOTE: a higher depth could possibly give more savings
work[it->res].assignIfDuplicate(*b_it++,depth);
}
}
}
}
void simplify(SXMatrix &ex){
// simplify all non-zero elements
for(int el=0; el<ex.size(); ++el)
simplify(ex.at(el));
}
