Exemplo n.º 1
0
 void SXNode::safe_delete(SXNode* n) {
   // Quick return if more owners
   if (n->count>0) return;
   // Delete straight away if it doesn't have any dependencies
   if (!n->n_dep()) {
     delete n;
     return;
   }
   // Stack of expressions to be deleted
   std::stack<SXNode*> deletion_stack;
   // Add the node to the deletion stack
   deletion_stack.push(n);
   // Process stack
   while (!deletion_stack.empty()) {
     // Top element
     SXNode *t = deletion_stack.top();
     // Check if the top element has dependencies with dependencies
     bool added_to_stack = false;
     for (casadi_int c2=0; c2<t->n_dep(); ++c2) { // for all dependencies of the dependency
       // Get the node of the dependency of the top element
       // and remove it from the smart pointer
       SXNode *n2 = t->dep(c2).assignNoDelete(casadi_limits<SXElem>::nan);
       // Check if this is the only reference to the element
       if (n2->count == 0) {
         // Check if unary or binary
         if (!n2->n_dep()) {
           // Delete straight away if not binary
           delete n2;
         } else {
           // Add to deletion stack
           deletion_stack.push(n2);
           added_to_stack = true;
         }
       }
     }
     // Delete and pop from stack if nothing added to the stack
     if (!added_to_stack) {
       delete deletion_stack.top();
       deletion_stack.pop();
     }
   }
 }
Exemplo n.º 2
0
    /** \brief Destructor
    This is a rather complex destructor which is necessary since the default destructor 
    can cause stack overflow due to recursive calling.
    */
    virtual ~BinarySX(){
      // Start destruction method if any of the dependencies has dependencies
      for(int c1=0; c1<2; ++c1){
        // Get the node of the dependency and remove it from the smart pointer
        SXNode* n1 = dep(c1).assignNoDelete(casadi_limits<SX>::nan);
        
        // Check if this was the last reference
        if(n1->count==0){

          // Check if binary
          if(!n1->hasDep()){ // n1 is not binary

            delete n1; // Delete stright away 

          } else { // n1 is binary
            
            // Stack of experssions to be deleted
            std::stack<SXNode*> deletion_stack;
            
            // Add the node to the deletion stack
            deletion_stack.push(n1);
            
            // Process stack
            while(!deletion_stack.empty()){
              
              // Top element
              SXNode *t = deletion_stack.top();
              
              // Check if the top element has dependencies with dependencies
              bool added_to_stack = false;
              for(int c2=0; c2<t->ndep(); ++c2){ // for all dependencies of the dependency
                
                // Get the node of the dependency of the top element and remove it from the smart pointer
                SXNode *n2 = t->dep(c2).assignNoDelete(casadi_limits<SX>::nan);
                
                // Check if this is the only reference to the element
                if(n2->count == 0){
                  
                  // Check if binary
                  if(!n2->hasDep()){
                    
                    // Delete stright away if not binary
                    delete n2;
                    
                  } else {
                    
                    // Add to deletion stack
                    deletion_stack.push(n2);
                    added_to_stack = true;
                  }
                }
              }
              
              // Delete and pop from stack if nothing added to the stack
              if(!added_to_stack){
                delete deletion_stack.top();
                deletion_stack.pop();
              }
            } // while
          }
        }
      }
    }
Exemplo n.º 3
0
void expand(const SXMatrix& ex2, SXMatrix &ww, SXMatrix& tt){
  casadi_assert(ex2.scalar());
  SX ex = ex2.toScalar();
  
  // Terms, weights and indices of the nodes that are already expanded
  std::vector<std::vector<SXNode*> > terms;
  std::vector<std::vector<double> > weights;
  std::map<SXNode*,int> indices;

  // Stack of nodes that are not yet expanded
  std::stack<SXNode*> to_be_expanded;
  to_be_expanded.push(ex.get());

  while(!to_be_expanded.empty()){ // as long as there are nodes to be expanded

    // Check if the last element on the stack is already expanded
   if (indices.find(to_be_expanded.top()) != indices.end()){
      // Remove from stack
      to_be_expanded.pop();
      continue;
    }

    // Weights and terms
    std::vector<double> w; // weights
    std::vector<SXNode*> f; // terms

    if(to_be_expanded.top()->isConstant()){ // constant nodes are seen as multiples of one
      w.push_back(to_be_expanded.top()->getValue());
      f.push_back(casadi_limits<SX>::one.get());
    } else if(to_be_expanded.top()->isSymbolic()){ // symbolic nodes have weight one and itself as factor
      w.push_back(1);
      f.push_back(to_be_expanded.top());
    } else { // binary node

        casadi_assert(to_be_expanded.top()->hasDep()); // make sure that the node is binary

        // Check if addition, subtracton or multiplication
        SXNode* node = to_be_expanded.top();
        // If we have a binary node that we can factorize
        if(node->getOp() == OP_ADD || node->getOp() == OP_SUB || (node->getOp() == OP_MUL  && (node->dep(0)->isConstant() || node->dep(1)->isConstant()))){
          // Make sure that both children are factorized, if not - add to stack
          if (indices.find(node->dep(0).get()) == indices.end()){
            to_be_expanded.push(node->dep(0).get());
            continue;
          }
          if (indices.find(node->dep(1).get()) == indices.end()){
             to_be_expanded.push(node->dep(1).get());
             continue;
          }

          // Get indices of children
          int ind1 = indices[node->dep(0).get()];
          int ind2 = indices[node->dep(1).get()];
  
          // If multiplication
          if(node->getOp() == OP_MUL){
            double fac;
            if(node->dep(0)->isConstant()){ // Multiplication where the first factor is a constant
              fac = node->dep(0)->getValue();
              f = terms[ind2];
              w = weights[ind2];
            } else { // Multiplication where the second factor is a constant
              fac = node->dep(1)->getValue();
              f = terms[ind1];
              w = weights[ind1];
            }
            for(int i=0; i<w.size(); ++i) w[i] *= fac;

          } else { // if addition or subtraction
            if(node->getOp() == OP_ADD){          // Addition: join both sums
              f = terms[ind1];      f.insert(f.end(), terms[ind2].begin(), terms[ind2].end());
              w = weights[ind1];    w.insert(w.end(), weights[ind2].begin(), weights[ind2].end());
            } else {      // Subtraction: join both sums with negative weights for second term
              f = terms[ind1];      f.insert(f.end(), terms[ind2].begin(), terms[ind2].end());
              w = weights[ind1];
              w.reserve(f.size());
              for(int i=0; i<weights[ind2].size(); ++i) w.push_back(-weights[ind2][i]);
            }
          // Eliminate multiple elements
          std::vector<double> w_new; w_new.reserve(w.size());   // weights
          std::vector<SXNode*> f_new;  f_new.reserve(f.size());   // terms
          std::map<SXNode*,int> f_ind; // index in f_new

          for(int i=0; i<w.size(); i++){
            // Try to locate the node
            std::map<SXNode*,int>::iterator it = f_ind.find(f[i]);
            if(it == f_ind.end()){ // if the term wasn't found
              w_new.push_back(w[i]);
              f_new.push_back(f[i]);
              f_ind[f[i]] = f_new.size()-1;
            } else { // if the term already exists
              w_new[it->second] += w[i]; // just add the weight
            }
          }
          w = w_new;
          f = f_new;
        }
      } else { // if we have a binary node that we cannot factorize
        // By default, 
        w.push_back(1);
        f.push_back(node);

      }
    }

    // Save factorization of the node
    weights.push_back(w);
    terms.push_back(f);
    indices[to_be_expanded.top()] = terms.size()-1;

    // Remove node from stack
    to_be_expanded.pop();
  }

  // Save expansion to output
  int thisind = indices[ex.get()];
  ww = SXMatrix(weights[thisind]);

  vector<SX> termsv(terms[thisind].size());
  for(int i=0; i<termsv.size(); ++i)
    termsv[i] = SX::create(terms[thisind][i]);
  tt = SXMatrix(termsv);
}
Exemplo n.º 4
0
  void SXFunctionInternal::init() {

    // Call the init function of the base class
    XFunctionInternal<SXFunction, SXFunctionInternal, SX, SXNode>::init();

    // Stack used to sort the computational graph
    stack<SXNode*> s;

    // All nodes
    vector<SXNode*> nodes;

    // Add the list of nodes
    int ind=0;
    for (vector<SX >::iterator it = outputv_.begin(); it != outputv_.end(); ++it, ++ind) {
      int nz=0;
      for (vector<SXElement>::iterator itc = it->begin(); itc != it->end(); ++itc, ++nz) {
        // Add outputs to the list
        s.push(itc->get());
        sort_depth_first(s, nodes);

        // A null pointer means an output instruction
        nodes.push_back(static_cast<SXNode*>(0));
      }
    }

    // Set the temporary variables to be the corresponding place in the sorted graph
    for (int i=0; i<nodes.size(); ++i) {
      if (nodes[i]) {
        nodes[i]->temp = i;
      }
    }

    // Sort the nodes by type
    constants_.clear();
    operations_.clear();
    for (vector<SXNode*>::iterator it = nodes.begin(); it != nodes.end(); ++it) {
      SXNode* t = *it;
      if (t) {
        if (t->isConstant())
          constants_.push_back(SXElement::create(t));
        else if (!t->isSymbolic())
          operations_.push_back(SXElement::create(t));
      }
    }

    // Use live variables?
    bool live_variables = getOption("live_variables");

    // Input instructions
    vector<pair<int, SXNode*> > symb_loc;

    // Current output and nonzero, start with the first one
    int curr_oind, curr_nz=0;
    for (curr_oind=0; curr_oind<outputv_.size(); ++curr_oind) {
      if (outputv_[curr_oind].nnz()!=0) {
        break;
      }
    }

    // Count the number of times each node is used
    vector<int> refcount(nodes.size(), 0);

    // Get the sequence of instructions for the virtual machine
    algorithm_.resize(0);
    algorithm_.reserve(nodes.size());
    for (vector<SXNode*>::iterator it=nodes.begin(); it!=nodes.end(); ++it) {
      // Current node
      SXNode* n = *it;

      // New element in the algorithm
      AlgEl ae;

      // Get operation
      ae.op = n==0 ? OP_OUTPUT : n->getOp();

      // Get instruction
      switch (ae.op) {
      case OP_CONST: // constant
        ae.d = n->getValue();
        ae.i0 = n->temp;
        break;
      case OP_PARAMETER: // a parameter or input
        symb_loc.push_back(make_pair(algorithm_.size(), n));
        ae.i0 = n->temp;
        break;
      case OP_OUTPUT: // output instruction
        ae.i0 = curr_oind;
        ae.i1 = outputv_[curr_oind].at(curr_nz)->temp;
        ae.i2 = curr_nz;

        // Go to the next nonzero
        curr_nz++;
        if (curr_nz>=outputv_[curr_oind].nnz()) {
          curr_nz=0;
          curr_oind++;
          for (; curr_oind<outputv_.size(); ++curr_oind) {
            if (outputv_[curr_oind].nnz()!=0) {
              break;
            }
          }
        }
        break;
      default:       // Unary or binary operation
        ae.i0 = n->temp;
        ae.i1 = n->dep(0).get()->temp;
        ae.i2 = n->dep(1).get()->temp;
      }

      // Number of dependencies
      int ndeps = casadi_math<double>::ndeps(ae.op);

      // Increase count of dependencies
      for (int c=0; c<ndeps; ++c) {
        refcount.at(c==0 ? ae.i1 : ae.i2)++;
      }
      // Add to algorithm
      algorithm_.push_back(ae);
    }

    // Place in the work vector for each of the nodes in the tree (overwrites the reference counter)
    vector<int> place(nodes.size());

    // Stack with unused elements in the work vector
    stack<int> unused;

    // Work vector size
    size_t worksize = 0;

    // Find a place in the work vector for the operation
    for (vector<AlgEl>::iterator it=algorithm_.begin(); it!=algorithm_.end(); ++it) {

      // Number of dependencies
      int ndeps = casadi_math<double>::ndeps(it->op);

      // decrease reference count of children
      // reverse order so that the first argument will end up at the top of the stack
      for (int c=ndeps-1; c>=0; --c) {
        int ch_ind = c==0 ? it->i1 : it->i2;
        int remaining = --refcount.at(ch_ind);
        if (remaining==0) unused.push(place[ch_ind]);
      }

      // Find a place to store the variable
      if (it->op!=OP_OUTPUT) {
        if (live_variables && !unused.empty()) {
          // Try to reuse a variable from the stack if possible (last in, first out)
          it->i0 = place[it->i0] = unused.top();
          unused.pop();
        } else {
          // Allocate a new variable
          it->i0 = place[it->i0] = worksize++;
        }
      }

      // Save the location of the children
      for (int c=0; c<ndeps; ++c) {
        if (c==0) {
          it->i1 = place[it->i1];
        } else {
          it->i2 = place[it->i2];
        }
      }

      // If binary, make sure that the second argument is the same as the first one
      // (in order to treat all operations as binary) NOTE: ugly
      if (ndeps==1 && it->op!=OP_OUTPUT) {
        it->i2 = it->i1;
      }
    }

    if (verbose()) {
      if (live_variables) {
        userOut() << "Using live variables: work array is "
             <<  worksize << " instead of " << nodes.size() << endl;
      } else {
        userOut() << "Live variables disabled." << endl;
      }
    }

    // Allocate work vectors (symbolic/numeric)
    alloc_w(worksize);
    alloc();
    s_work_.resize(worksize);

    // Reset the temporary variables
    for (int i=0; i<nodes.size(); ++i) {
      if (nodes[i]) {
        nodes[i]->temp = 0;
      }
    }

    // Now mark each input's place in the algorithm
    for (vector<pair<int, SXNode*> >::const_iterator it=symb_loc.begin();
         it!=symb_loc.end(); ++it) {
      it->second->temp = it->first+1;
    }

    // Add input instructions
    for (int ind=0; ind<inputv_.size(); ++ind) {
      int nz=0;
      for (vector<SXElement>::iterator itc = inputv_[ind].begin();
          itc != inputv_[ind].end();
          ++itc, ++nz) {
        int i = itc->getTemp()-1;
        if (i>=0) {
          // Mark as input
          algorithm_[i].op = OP_INPUT;

          // Location of the input
          algorithm_[i].i1 = ind;
          algorithm_[i].i2 = nz;

          // Mark input as read
          itc->setTemp(0);
        }
      }
    }

    // Locate free variables
    free_vars_.clear();
    for (vector<pair<int, SXNode*> >::const_iterator it=symb_loc.begin();
         it!=symb_loc.end(); ++it) {
      if (it->second->temp!=0) {
        // Save to list of free parameters
        free_vars_.push_back(SXElement::create(it->second));

        // Remove marker
        it->second->temp=0;
      }
    }

    // Initialize just-in-time compilation for numeric evaluation using OpenCL
    just_in_time_opencl_ = getOption("just_in_time_opencl");
    if (just_in_time_opencl_) {
#ifdef WITH_OPENCL
      freeOpenCL();
      allocOpenCL();
#else // WITH_OPENCL
      casadi_error("Option \"just_in_time_opencl\" true requires CasADi "
                   "to have been compiled with WITH_OPENCL=ON");
#endif // WITH_OPENCL
    }

    // Initialize just-in-time compilation for sparsity propagation using OpenCL
    just_in_time_sparsity_ = getOption("just_in_time_sparsity");
    if (just_in_time_sparsity_) {
#ifdef WITH_OPENCL
      spFreeOpenCL();
      spAllocOpenCL();
#else // WITH_OPENCL
      casadi_error("Option \"just_in_time_sparsity\" true requires CasADi to "
                   "have been compiled with WITH_OPENCL=ON");
#endif // WITH_OPENCL
    }

    if (CasadiOptions::profiling && CasadiOptions::profilingBinary) {

      profileWriteName(CasadiOptions::profilingLog, this, getOption("name"),
                       ProfilingData_FunctionType_SXFunction, algorithm_.size());
      int alg_counter = 0;

      // Iterator to free variables
      vector<SXElement>::const_iterator p_it = free_vars_.begin();

      std::stringstream stream;
      for (vector<AlgEl>::const_iterator it = algorithm_.begin(); it!=algorithm_.end(); ++it) {
        stream.str("");
        if (it->op==OP_OUTPUT) {
          stream << "output[" << it->i0 << "][" << it->i2 << "] = @" << it->i1;
        } else {
          stream << "@" << it->i0 << " = ";
          if (it->op==OP_INPUT) {
            stream << "input[" << it->i1 << "][" << it->i2 << "]";
          } else {
            if (it->op==OP_CONST) {
              stream << it->d;
            } else if (it->op==OP_PARAMETER) {
              stream << *p_it++;
            } else {
              int ndep = casadi_math<double>::ndeps(it->op);
              casadi_math<double>::printPre(it->op, stream);
              for (int c=0; c<ndep; ++c) {
                if (c==0) {
                  stream << "@" << it->i1;
                } else {
                  casadi_math<double>::printSep(it->op, stream);
                  stream << "@" << it->i2;
                }

              }
              casadi_math<double>::printPost(it->op, stream);
            }
          }
        }
        stream << std::endl;
        profileWriteSourceLine(CasadiOptions::profilingLog, this,
                               alg_counter++, stream.str(), it->op);
      }
    }

    // Print
    if (verbose()) {
      userOut() << "SXFunctionInternal::init Initialized " << getOption("name") << " ("
           << algorithm_.size() << " elementary operations)" << endl;
    }
  }