static inline void
GradientImpl(const LRSDPFunction<SDPType>& function,
const arma::mat& coordinates,
const arma::vec& lambda,
const double sigma,
arma::mat& gradient)
{
// We can calculate the gradient in a smart way.
// L'(R, y, s) = 2 * S' * R
// with
// S' = C - sum_{i = 1}^{m} y'_i A_i
// y'_i = y_i - sigma * (Trace(A_i * (R R^T)) - b_i)
const arma::mat rrt = coordinates * trans(coordinates);
arma::mat s(function.SDP().C());
UpdateGradient(
s, rrt, function.SDP().SparseA(), function.SDP().SparseB(),
lambda, 0, sigma);
UpdateGradient(
s, rrt, function.SDP().DenseA(), function.SDP().DenseB(),
lambda, function.SDP().NumSparseConstraints(), sigma);
gradient = 2 * s * coordinates;
}
void tMercuryControlSeparator::resizeEvent(QResizeEvent*)
{
UpdateGradient();
}
