// $Id$
/* --------------------------------------------------------------------------
CppAD: C++ Algorithmic Differentiation: Copyright (C) 2003-15 Bradley M. Bell

CppAD is distributed under multiple licenses. This distribution is under
the terms of the
                    GNU General Public License Version 3.

A copy of this license is included in the COPYING file of this distribution.
Please visit http://www.coin-or.org/CppAD/ for information on other licenses.
-------------------------------------------------------------------------- */

// Test that reverse mode handles conditional expressions properly
// in that infinity and nans do not propagate thouh un-used case.

# include <cppad/cppad.hpp>

bool cond_exp_rev(void)
{	bool ok = true;
	using CppAD::vector;
	using CppAD::AD;

	AD<double> anan  = std::numeric_limits<double>::quiet_NaN();
	AD<double> azero = 0.0;


	size_t n = 2;
	vector< AD<double> > ax(n), ay;
	ax[0] = 1.0;
	ax[1] = anan;
	Independent(ax);

	// AbsOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], abs(ax[1]) ));

	// AcosOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], acos(ax[1]) ));

	// AddvvOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], ax[0] + ax[1] ));

	// AddpvOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], 1.0 + ax[1] ));

	// AsinOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], asin(ax[1]) ));

	// AtanOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], atan(ax[1]) ));

	// CosOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], cos(ax[1]) ));

	// CoshOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], cosh(ax[1]) ));

	// DivvvOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], ax[0] / ax[1] ));

	// DivpvOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], 1.0 / ax[1] ));

	// DivvpOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], ax[1] / 2.0 ));

	// ErfOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], erf(ax[1]) ));

	// ExpOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], exp(ax[1]) ));

	// LogOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], log(ax[1]) ));

	// MulvvOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], ax[0] * ax[1] ));

	// MulpvOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], 2.0 * ax[1] ));

	// PowvvOP
	// uses check in log, mul, and exp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], pow(ax[1], ax[1]) ));

	// PowvpOP
	// uses check in log, mul, and exp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], pow(ax[1], 2.0) ));

	// PowpvOP
	// uses check in log, mul, and exp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], pow(2.0, ax[1]) ));

	// SignOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], sign(ax[1]) ));

	// SinOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], sin(ax[1]) ));

	// SinhOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], sinh(ax[1]) ));

	// SqrtOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], sqrt(ax[1]) ));

	// SubvvOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], ax[0] - ax[1] ));

	// SubpvOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], 1.0 - ax[1] ));

	// SubvpOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], ax[1] - 1.0 ));

	// TanOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], tan(ax[1]) ));

	// TanhOp
	ay.push_back( CondExpGt(ax[0], azero, ax[0], tanh(ax[1]) ));

	// create f : x -> y
	size_t m = ay.size();
	CppAD::ADFun<double> f(ax, ay);

	// weighting vector and reverse mode derivative
	vector<double> w(m), dw(n);
	for(size_t i = 0; i < m; i++)
		w[i] = 0.0;

	// check DivvOp
	for(size_t i = 0; i < m; i++)
	{	w[i] = 1.0;
		dw = f.Reverse(1, w);
		ok &= dw[0] == 1.0;
		ok &= dw[1] == 0.0;
		w[i] = 0.0;
	}

	return ok;
}
