void CGraphUT::testLin()
{
CNode *n0, *n1, *n2, *n3;
CGraph cgraph;
int error = 0;
VariablePtr v0 = (VariablePtr) new Variable(0, 0, 0.0, 10.0, Continuous, "x0");
VariablePtr v1 = (VariablePtr) new Variable(1, 1, 0.0, 10.0, Continuous, "x1");
VariablePtr v2 = (VariablePtr) new Variable(2, 2, 0.0, 10.0, Continuous, "x2");
VariablePtr v3 = (VariablePtr) new Variable(3, 3, 0.0, 10.0, Continuous, "x3");
double x[4] = {1.0, 2.0, 5.0, 7.0};
double g[4] = {0.0, 0.0, 0.0, 0.0};
double gexp[4] = {1.0, 1.0, 5.4, -1.0};
n0 = cgraph.newNode(v0);
n1 = cgraph.newNode(v0);
CPPUNIT_ASSERT(n0 == n1);
n1 = cgraph.newNode(v1);
n2 = cgraph.newNode(v1);
CPPUNIT_ASSERT(n2 == n1);
CPPUNIT_ASSERT(n0 != n1);
n2 = cgraph.newNode(OpPlus, n0, n1);
n3 = cgraph.newNode(5.4);
n0 = cgraph.newNode(v2);
n3 = cgraph.newNode(OpMult, n3, n0);
n3 = cgraph.newNode(OpPlus, n2, n3); // n3 = x0 + x1 + 5.4*x2
n0 = cgraph.newNode(v3);
n0 = cgraph.newNode(OpMinus, n3, n0); // n0 = x0 + x1 + 5.4*x2 - x3
cgraph.setOut(n0);
cgraph.finalize();
CPPUNIT_ASSERT(cgraph.numVars() == 4);
CPPUNIT_ASSERT(cgraph.getType() == Linear);
CPPUNIT_ASSERT(fabs(cgraph.eval(x, &error) - 23.0)<1e-10);
CPPUNIT_ASSERT(0==error);
cgraph.evalGradient(x, g, &error);
CPPUNIT_ASSERT(0==error);
for (UInt i=0; i<4; ++i) {
CPPUNIT_ASSERT(fabs(g[i]-gexp[i])<1e-10);
}
x[0] = 0.0; x[1] = 2.0; x[2] = 0.0; x[3] = 7.0;
g[0] = 0.0; g[1] = 0.0; g[2] = 0.0; g[3] = 0.0;
cgraph.evalGradient(x, g, &error);
for (UInt i=0; i<4; ++i) {
CPPUNIT_ASSERT(fabs(g[i]-gexp[i])<1e-10);
}
CPPUNIT_ASSERT(0==error);
CPPUNIT_ASSERT(fabs(n0->getVal()+5.0)<1e-10);
CPPUNIT_ASSERT(fabs(cgraph.eval(x,&error)+5.0)<1e-10);
}
