/** \brief Create a binary expression */
inline static SXElement create(unsigned char op, const SXElement& dep0, const SXElement& dep1) {
if (dep0.isConstant() && dep1.isConstant()) {
// Evaluate constant
double dep0_val = dep0.getValue();
double dep1_val = dep1.getValue();
double ret_val;
casadi_math<double>::fun(op, dep0_val, dep1_val, ret_val);
return ret_val;
} else {
// Expression containing free variables
return SXElement::create(new BinarySX(op, dep0, dep1));
}
}
SXElement SXElement::__div__(const SXElement& y) const {
// Only simplifications that do not result in extra nodes area allowed
if (!CasadiOptions::simplification_on_the_fly) return BinarySX::create(OP_DIV, *this, y);
if (y->isZero()) // term2 is zero
return casadi_limits<SXElement>::nan;
else if (node->isZero()) // term1 is zero
return 0;
else if (y->isOne()) // term2 is one
return *this;
else if (y->isMinusOne())
return -(*this);
else if (isEqual(y, SXNode::eq_depth_)) // terms are equal
return 1;
else if (isDoubled() && y.isEqual(2))
return node->dep(0);
else if (isOp(OP_MUL) && y.isEqual(node->dep(0), SXNode::eq_depth_))
return node->dep(1);
else if (isOp(OP_MUL) && y.isEqual(node->dep(1), SXNode::eq_depth_))
return node->dep(0);
else if (node->isOne())
return y.inv();
else if (y.hasDep() && y.getOp()==OP_INV)
return (*this)*y.inv();
else if (isDoubled() && y.isDoubled())
return node->dep(0) / y->dep(0);
else if (y.isConstant() && hasDep() && getOp()==OP_DIV && getDep(1).isConstant() &&
y.getValue()*getDep(1).getValue()==1) // (x/5)/0.2
return getDep(0);
else if (y.hasDep() && y.getOp()==OP_MUL &&
y.getDep(1).isEqual(*this, SXNode::eq_depth_)) // x/(2*x) = 1/2
return BinarySX::create(OP_DIV, 1, y.getDep(0));
else if (hasDep() && getOp()==OP_NEG &&
getDep(0).isEqual(y, SXNode::eq_depth_)) // (-x)/x = -1
return -1;
else if (y.hasDep() && y.getOp()==OP_NEG &&
y.getDep(0).isEqual(*this, SXNode::eq_depth_)) // x/(-x) = 1
return -1;
else if (y.hasDep() && y.getOp()==OP_NEG && hasDep() &&
getOp()==OP_NEG && getDep(0).isEqual(y.getDep(0), SXNode::eq_depth_)) // (-x)/(-x) = 1
return 1;
else if (isOp(OP_DIV) && y.isEqual(node->dep(0), SXNode::eq_depth_))
return node->dep(1).inv();
else // create a new branch
return BinarySX::create(OP_DIV, *this, y);
}
