[gnumeric] nlsolve: minor improvements.

[Morten Welinder <mortenw src gnome org>]

commit 19df5fcbc8672314cf1edeeeba2c5424e09975e9
Author: Morten Welinder <terra gnome org>
Date:   Sun May 23 11:27:45 2010 -0400

    nlsolve: minor improvements.

 plugins/nlsolve/ChangeLog     |    5 +++++
 plugins/nlsolve/gnm-nlsolve.c |   24 ++++++++++--------------
 src/dialogs/dialog-solver.c   |   12 +++---------
 3 files changed, 18 insertions(+), 23 deletions(-)
---
diff --git a/plugins/nlsolve/ChangeLog b/plugins/nlsolve/ChangeLog
index 45e20de..2b09e8f 100644
--- a/plugins/nlsolve/ChangeLog
+++ b/plugins/nlsolve/ChangeLog
@@ -1,3 +1,8 @@
+2010-05-23  Morten Welinder  <terra gnome org>
+
+	* gnm-nlsolve.c (gnm_nlsolve_idle): Use the axis-method even if
+	the Hessian is singular.  Restore x0 if we fail to improve.
+
 2010-05-21  Morten Welinder  <terra gnome org>
 
 	* Initial Implementation
diff --git a/plugins/nlsolve/gnm-nlsolve.c b/plugins/nlsolve/gnm-nlsolve.c
index 8ef492a..1825b74 100644
--- a/plugins/nlsolve/gnm-nlsolve.c
+++ b/plugins/nlsolve/gnm-nlsolve.c
@@ -345,13 +345,11 @@ gnm_nlsolve_idle (gpointer data)
 
 	d = g_new (gnm_float, n);
 	ok = (gnm_linear_solve (H, g, n, d) == 0);
-	if (!ok)
-		goto stop;
-
-	if (nl->debug)
-		print_vector ("Delta", d, n);
-
-	ok = try_direction (nl, x0, d);
+	if (ok) {
+		if (nl->debug)
+			print_vector ("Delta", d, n);
+		ok = try_direction (nl, x0, d);
+	}
 
 	if (!ok) {
 		int i, j;
@@ -380,6 +378,10 @@ gnm_nlsolve_idle (gpointer data)
 	}
 
 	if (!ok) {
+		int i;
+		for (i = 0; i < n; i++)
+			set_value (nl, i, x0[i]);
+
 		gnm_solver_set_status (sol, GNM_SOLVER_STATUS_DONE);
 		call_again = FALSE;
 	}
@@ -389,7 +391,6 @@ gnm_nlsolve_idle (gpointer data)
 		call_again = FALSE;
 	}
 
-out:
 	g_free (d);
 	g_free (x0);
 	g_free (g);
@@ -398,11 +399,6 @@ out:
 	g_free (H);
 
 	return call_again;
-
-stop:
-	gnm_solver_stop (sol, NULL);
-	call_again = FALSE;
-	goto out;
 }
 
 static gboolean
@@ -460,7 +456,7 @@ nlsolve_solver_factory (GnmSolverFactory *factory, GnmSolverParameters *params)
 
 	nl->debug = gnm_solver_debug ();
 	nl->eps = gnm_pow2 (-25);
-	nl->max_iter = 100;
+	nl->max_iter = 1000;
 	nl->min_factor = 1e-10;
 
 	nl->target = gnm_solver_param_get_target_cell (params);
diff --git a/src/dialogs/dialog-solver.c b/src/dialogs/dialog-solver.c
index bd6abd5..2bc7acb 100644
--- a/src/dialogs/dialog-solver.c
+++ b/src/dialogs/dialog-solver.c
@@ -974,6 +974,9 @@ dialog_init (SolverState *state)
 	for (i = 0; model_type_group[i]; i++) {
 		const char *bname = model_type_group[i];
 		GtkWidget *w = glade_xml_get_widget(state->gui, bname);
+		gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (w),
+					      param->options.model_type ==
+					      (GnmSolverModelType)i);
 		g_signal_connect (G_OBJECT (w), "clicked",
 				  G_CALLBACK (cb_dialog_model_type_clicked), state);
 	}
@@ -1116,15 +1119,6 @@ dialog_init (SolverState *state)
 		glade_xml_get_widget(state->gui, "min_button")),
 			param->problem_type == GNM_SOLVER_MINIMIZE);
 	gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (
-		glade_xml_get_widget(state->gui, "lp_model_button")),
-			param->options.model_type == GNM_SOLVER_LP);
-	gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (
-		glade_xml_get_widget(state->gui, "qp_model_button")),
-			param->options.model_type == GNM_SOLVER_QP);
-	gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (
-		glade_xml_get_widget(state->gui, "nlp_model_button")),
-			param->options.model_type == GNM_SOLVER_NLP);
-	gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (
 		glade_xml_get_widget(state->gui, "no_scenario")),
 			! param->options.add_scenario);
 	gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (