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Gradient at solution is zero !

release/4.3a0
Frank Dellaert 2009-12-11 02:59:09 +00:00
parent 532ea0ae36
commit 4af2382105
1 changed files with 11 additions and 5 deletions
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16
cpp/testGaussianFactorGraph.cpp
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@ -548,15 +548,21 @@ TEST( GaussianFactorGraph, gradient )
// 2*f(x) = 100*(x1+c["x1"])^2 + 100*(x2-x1-[0.2;-0.1])^2 + 25*(l1-x1-[0.0;0.2])^2 + 25*(l1-x2-[-0.2;0.3])^2
// worked out: df/dx1 = 100*[0.1;0.1] + 100*[0.2;-0.1]) + 25*[0.0;0.2] = [10+20;10-10+5] = [30;5]
expected.insert("x1",Vector_(2,30.0,5.0));
// from working implementation:
expected.insert("x2",Vector_(2,-25.0, 17.5));
expected.insert("l1",Vector_(2, 5.0,-12.5));
// calculate the gradient at delta=0
VectorConfig delta = createZeroDelta();
VectorConfig actual = fg.gradient(delta);
// Check the gradient at delta=0
VectorConfig zero = createZeroDelta();
VectorConfig actual = fg.gradient(zero);
CHECK(assert_equal(expected,actual));
// Check the gradient at the solution (should be zero)
Ordering ord;
ord += "x2","l1","x1";
GaussianFactorGraph fg2 = createGaussianFactorGraph();
VectorConfig solution = fg2.optimize(ord); // destructive
VectorConfig actual2 = fg.gradient(solution);
CHECK(assert_equal(zero,actual2));
}
/* ************************************************************************* */