def iterate(cself, svm, classes): cself.mention('Training SVM...') D = spdiag(classes) qp.update_H(D * K * D) qp.update_Aeq(classes.T) alphas, obj = qp.solve(cself.verbose) # Construct SVM from solution svm = SVM(kernel=self.kernel, gamma=self.gamma, p=self.p, verbose=self.verbose, sv_cutoff=self.sv_cutoff) svm._X = bs.instances svm._y = classes svm._alphas = alphas svm._objective = obj svm._compute_separator(K) svm._K = K cself.mention('Recomputing classes...') p_conf = svm._predictions[-bs.L_p:] pos_classes = np.vstack([_update_classes(part) for part in partition(p_conf, bs.pos_groups)]) new_classes = np.vstack([-np.ones((bs.L_n, 1)), pos_classes]) class_changes = round(np.sum(np.abs(classes - new_classes) / 2)) cself.mention('Class Changes: %d' % class_changes) if class_changes == 0: return None, svm return {'svm': svm, 'classes': new_classes}, None
def iterate(cself, svm, selectors, instances, K): cself.mention('Training SVM...') alphas, obj = qp.solve(cself.verbose) # Construct SVM from solution svm = SVM(kernel=self.kernel, gamma=self.gamma, p=self.p, verbose=self.verbose, sv_cutoff=self.sv_cutoff) svm._X = instances svm._y = classes svm._alphas = alphas svm._objective = obj svm._compute_separator(K) svm._K = K cself.mention('Recomputing classes...') p_confs = svm.predict(bs.pos_instances) pos_selectors = bs.L_n + np.array([ l + np.argmax(p_confs[l:u]) for l, u in slices(bs.pos_groups) ]) new_selectors = np.hstack([neg_selectors, pos_selectors]) if selectors is None: sel_diff = len(new_selectors) else: sel_diff = np.nonzero(new_selectors - selectors)[0].size cself.mention('Selector differences: %d' % sel_diff) if sel_diff == 0: return None, svm elif sel_diff > 5: # Clear results to avoid a # bad starting point in # the next iteration qp.clear_results() cself.mention('Updating QP...') indices = (new_selectors, ) K = K_all[indices].T[indices].T D = spdiag(classes) qp.update_H(D * K * D) return { 'svm': svm, 'selectors': new_selectors, 'instances': bs.instances[indices], 'K': K }, None
def iterate(cself, svm, selectors, instances, K): cself.mention('Training SVM...') alphas, obj = qp.solve(cself.verbose) # Construct SVM from solution svm = SVM(kernel=self.kernel, gamma=self.gamma, p=self.p, verbose=self.verbose, sv_cutoff=self.sv_cutoff) svm._X = instances svm._y = classes svm._alphas = alphas svm._objective = obj svm._compute_separator(K) svm._K = K cself.mention('Recomputing classes...') p_confs = svm.predict(bs.pos_instances) pos_selectors = bs.L_n + np.array([l + np.argmax(p_confs[l:u]) for l, u in slices(bs.pos_groups)]) new_selectors = np.hstack([neg_selectors, pos_selectors]) if selectors is None: sel_diff = len(new_selectors) else: sel_diff = np.nonzero(new_selectors - selectors)[0].size cself.mention('Selector differences: %d' % sel_diff) if sel_diff == 0: return None, svm elif sel_diff > 5: # Clear results to avoid a # bad starting point in # the next iteration qp.clear_results() cself.mention('Updating QP...') indices = (new_selectors,) K = K_all[indices].T[indices].T D = spdiag(classes) qp.update_H(D * K * D) return {'svm': svm, 'selectors': new_selectors, 'instances': bs.instances[indices], 'K': K}, None