diff --git a/gtsam/navigation/NavState.cpp b/gtsam/navigation/NavState.cpp index a955cc7dd..23a72a6bb 100644 --- a/gtsam/navigation/NavState.cpp +++ b/gtsam/navigation/NavState.cpp @@ -246,11 +246,11 @@ NavState NavState::update(const Vector3& omega, const Vector3& acceleration, Matrix39 D_xiP_state; double dt22 = 0.5 * dt * dt; dR(xi) << dt * omega; - dP(xi) << dt * bodyVelocity(D_xiP_state) + dt22 * acceleration; + dP(xi) << dt * bodyVelocity(F ? &D_xiP_state : 0) + dt22 * acceleration; dV(xi) << dt * acceleration; Matrix9 D_result_xi; - NavState result = retract(xi, F, D_result_xi); + NavState result = retract(xi, F, G1 || G2 ? &D_result_xi : 0); // Derivative wrt state is computed by retract directly // However, as dP(xi) also depends on state, we need to add that contribution @@ -259,11 +259,19 @@ NavState NavState::update(const Vector3& omega, const Vector3& acceleration, } // derivative wrt omega if (G1) { - *G1 = dt * D_result_xi.leftCols<3>(); + // D_result_dRxi = D_result_xi.leftCols<3>() + // D_dRxi_omega = dt * I_3x3 + // *G1 = D_result_omega = D_result_dRxi * D_dRxi_omega + *G1 = D_result_xi.leftCols<3>() * dt; } // derivative wrt acceleration if (G2) { - *G2 = dt22 * D_result_xi.middleCols<3>(3) + dt * D_result_xi.rightCols<3>(); + // D_result_dPxi = D_result_xi.middleCols<3>(3) + // D_dPxi_acc = dt22 * I_3x3 + // D_result_dVxi = D_result_xi.rightCols<3>() + // D_dVxi_acc = dt * I_3x3 + // *G2 = D_result_acc = D_result_dPxi * D_dPxi_acc + D_result_dVxi * D_dVxi_acc + *G2 = D_result_xi.middleCols<3>(3) * dt22 + D_result_xi.rightCols<3>() * dt; } return result; }