/*------------------------------------------------------------*/
void AzsSvrg::flushDelta()
{
if (momentum > 0) { /* use momentum */
check_ws("flushDelta with momentum");
m_w_delta.multiply(-eta);
m_w_delta.add(&m_w, -eta*lam);
m_w_delta.add(&m_w_delta_prev, momentum);
m_w.add(&m_w_delta);
m_w_delta_prev.set(&m_w_delta);
}
else { /* don't use momentum */
ws *= (1 - lam*eta);
m_w.add(&m_w_delta, -eta/ws);
}
m_w_delta.zeroOut();
if (ws < 1e-10) {
flush_ws();
}
}
/*------------------------------------------------------------*/
void AzpLmSgd::flushDelta(const AzpLmParam &p, const AzpLmSgd_Param &ps)
{
if (p.dont_update()) return;
if (grad_num <= 0) return;
double etab = (ps.etab_coeff == 1) ? ps.eta : ps.eta*ps.etab_coeff;
if (ps.do_fast_flush && ps.momentum > 0) {
check_ws("flushDelta with momentum (fast_flush)");
double mm = MAX(0,ps.momentum);
if (p.reg_L2 > 0 && p.reg_L2init <= 0) {
m_w_dlt.add(mm, &m_w_grad, -ps.eta/(double)grad_num, &m_w, -ps.eta*p.reg_L2);
}
else {
m_w_dlt.add(mm, &m_w_grad, -ps.eta/(double)grad_num);
if (!p.no_regadd()) {
add_reg_grad(p, ps.eta, &m_w, &m_w_dlt, &m_w_init);
}
}
m_w.add(&m_w_dlt);
v_i_dlt.add(mm, &v_i_grad, -etab/(double)grad_num);
if (p.do_reg_intercept && !p.no_regadd()) {
add_reg_grad(p, etab, &v_i, &v_i_dlt, &v_i_init); /* regularization */
}
v_i.add(&v_i_dlt);
do_gradpart = false;
}
else if (ps.momentum > 0 || p.reg_L2init > 0) { /* use momentum; slower; keeping this for compatibility */
check_ws("flushDelta with momentum");
double mm = MAX(0,ps.momentum);
m_w_grad.multiply(-ps.eta/(double)grad_num);
add_reg_grad(p, ps.eta, &m_w, &m_w_grad, &m_w_init); /* regularization */
m_w_grad.add(&m_w_dlt, mm);
m_w.add(&m_w_grad);
m_w_dlt.set_chk(&m_w_grad);
v_i_grad.multiply(-etab/(double)grad_num);
if (p.do_reg_intercept) {
add_reg_grad(p, etab, &v_i, &v_i_grad, &v_i_init); /* regularization */
}
v_i_grad.add(&v_i_dlt, mm);
v_i.add(&v_i_grad);
v_i_dlt.set_chk(&v_i_grad);
do_gradpart = false;
}
else { /* don't use momentum */
regularize(p, ps.eta, etab);
if (doing_partial() && do_gradpart) {
m_w.add_s2d(&m_w_grad, ia_p2w.point(), ia_p2w.size(), -ps.eta/(double)grad_num/ws);
v_i.add_s2d(&v_i_grad, ia_p2w.point(), ia_p2w.size(), -etab/(double)grad_num);
}
else {
m_w.add(&m_w_grad, -ps.eta/(double)grad_num/ws);
v_i.add(&v_i_grad, -etab/(double)grad_num);
}
do_gradpart = doing_partial();
}
if (p.reg_L2const > 0) do_l2const(p);
grad_num = 0;
if (ws < 1e-4) flush_ws();
}
