[gnumeric] Solver: move some code around.

[Morten Welinder <mortenw src gnome org>]

commit ba86400f3f311b6e5978196651d92c05bfcf87a4
Author: Morten Welinder <terra gnome org>
Date:   Wed Apr 29 11:00:13 2015 -0400

    Solver: move some code around.

 plugins/nlsolve/gnm-nlsolve.c |   36 ++---------
 src/tools/gnm-solver.c        |  145 ++++++++++++++++++++++++-----------------
 src/tools/gnm-solver.h        |    6 +-
 3 files changed, 94 insertions(+), 93 deletions(-)
---
diff --git a/plugins/nlsolve/gnm-nlsolve.c b/plugins/nlsolve/gnm-nlsolve.c
index 022d3bf..ee05b6d 100644
--- a/plugins/nlsolve/gnm-nlsolve.c
+++ b/plugins/nlsolve/gnm-nlsolve.c
@@ -111,8 +111,8 @@ set_vector (GnmNlsolve *nl, const gnm_float *xs)
 static gnm_float
 get_value (GnmNlsolve *nl)
 {
-       /* nl->isol has been taught to flip sign if needed.  */
-       return gnm_iter_solver_get_target_value (nl->isol);
+       /* nl->sol has been taught to flip sign if needed.  */
+       return gnm_solver_get_target_value (nl->sol);
 }
 
 static void
@@ -157,34 +157,7 @@ gnm_nlsolve_prepare (GnmSolver *sol, WorkbookControl *wbc, GError **err,
 static gnm_float *
 compute_gradient (GnmNlsolve *nl, const gnm_float *xs)
 {
-       gnm_float *g;
-       gnm_float y0;
-       const int n = nl->n;
-       int i;
-
-       set_vector (nl, xs);
-       y0 = get_value (nl);
-
-       g = g_new (gnm_float, n);
-       for (i = 0; i < n; i++) {
-               gnm_float x0 = xs[i];
-               gnm_float dx;
-               gnm_float y1;
-               gnm_float eps = gnm_pow2 (-25);
-
-               if (x0 == 0)
-                       dx = eps;
-               else
-                       dx = gnm_abs (x0) * eps;
-
-               set_value (nl, i, x0 + dx);
-               y1 = get_value (nl);
-               g[i] = (y1 - y0) / dx;
-
-               set_value (nl, i, x0);
-       }
-
-       return g;
+       return gnm_solver_compute_gradient (nl->sol, xs);
 }
 
 static gnm_float **
@@ -590,7 +563,8 @@ nlsolve_solver_factory (GnmSolverFactory *factory, GnmSolverParameters *params)
 
        gnm_solver_iterator_compound_add (citer, gnm_solver_iterator_new_polish (isol), 0);
 
-       isol->iterator = GNM_SOLVER_ITERATOR (citer);
+       gnm_iter_solver_set_iterator (isol, GNM_SOLVER_ITERATOR (citer));
+       g_object_unref (citer);
 
        nl->sol = sol;
        nl->isol = isol;
diff --git a/src/tools/gnm-solver.c b/src/tools/gnm-solver.c
index c0f3f34..e32836f 100644
--- a/src/tools/gnm-solver.c
+++ b/src/tools/gnm-solver.c
@@ -5,6 +5,7 @@
 #include "expr.h"
 #include "sheet.h"
 #include "workbook.h"
+#include "rangefunc.h"
 #include "ranges.h"
 #include "gutils.h"
 #include "gnm-solver.h"
@@ -781,7 +782,8 @@ enum {
        SOL_PROP_PARAMS,
        SOL_PROP_RESULT,
        SOL_PROP_STARTTIME,
-       SOL_PROP_ENDTIME
+       SOL_PROP_ENDTIME,
+       SOL_PROP_FLIP_SIGN
 };
 
 static GObjectClass *gnm_solver_parent_class;
@@ -875,6 +877,10 @@ gnm_solver_get_property (GObject *object, guint property_id,
                g_value_set_double (value, sol->endtime);
                break;
 
+       case SOL_PROP_FLIP_SIGN:
+               g_value_set_boolean (value, sol->flip_sign);
+               break;
+
        default:
                G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
                break;
@@ -914,6 +920,10 @@ gnm_solver_set_property (GObject *object, guint property_id,
                sol->endtime = g_value_get_double (value);
                break;
 
+       case SOL_PROP_FLIP_SIGN:
+               sol->flip_sign = g_value_get_boolean (value);
+               break;
+
        default:
                G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
                break;
@@ -1665,6 +1675,13 @@ gnm_solver_create_report (GnmSolver *solver, const char *name)
 #undef ADD_HEADER
 #undef MARK_BAD
 
+/**
+ * gnm_solver_get_target_value:
+ * @isol: solver
+ *
+ * Returns: the current value of the target cell, possibly with the sign
+ * flipped.
+ */
 gnm_float
 gnm_solver_get_target_value (GnmSolver *solver)
 {
@@ -1673,9 +1690,10 @@ gnm_solver_get_target_value (GnmSolver *solver)
        gnm_cell_eval (solver->target);
        v = solver->target->value;
 
-       if (VALUE_IS_NUMBER (v) || VALUE_IS_EMPTY (v))
-               return value_get_as_float (v);
-       else
+       if (VALUE_IS_NUMBER (v) || VALUE_IS_EMPTY (v)) {
+               gnm_float y = value_get_as_float (v);
+               return solver->flip_sign ? 0 - y : y;
+       } else
                return gnm_nan;
 }
 
@@ -1703,6 +1721,49 @@ gnm_solver_set_vars (GnmSolver *sol, gnm_float const *xs)
                gnm_solver_set_var (sol, i, xs[i]);
 }
 
+/**
+ * gnm_solver_compute_gradient:
+ * @sol: Solver
+ * @xs: Point to compute gradient at
+ *
+ * Returns: (transfer full): A vector containing the gradient.  This
+ * function takes the flip_sign into account.  Note, that this is a
+ * numerical approximation.
+ */
+gnm_float *
+gnm_solver_compute_gradient (GnmSolver *sol, gnm_float const *xs)
+{
+       gnm_float *g;
+       gnm_float y0;
+       const int n = sol->input_cells->len;
+       int i;
+
+       gnm_solver_set_vars (sol, xs);
+       y0 = gnm_solver_get_target_value (sol);
+
+       g = g_new (gnm_float, n);
+       for (i = 0; i < n; i++) {
+               gnm_float x0 = xs[i];
+               gnm_float dx;
+               gnm_float y1;
+               gnm_float eps = gnm_pow2 (-25);
+
+               if (x0 == 0)
+                       dx = eps;
+               else
+                       dx = gnm_abs (x0) * eps;
+
+               gnm_solver_set_var (sol, i, x0 + dx);
+               y1 = gnm_solver_get_target_value (sol);
+               g[i] = (y1 - y0) / dx;
+
+               gnm_solver_set_var (sol, i, x0);
+       }
+
+       return g;
+}
+
+
 static void
 gnm_solver_class_init (GObjectClass *object_class)
 {
@@ -1763,6 +1824,13 @@ gnm_solver_class_init (GObjectClass *object_class)
                                     GSF_PARAM_STATIC |
                                     G_PARAM_READWRITE));
 
+       g_object_class_install_property (object_class, SOL_PROP_FLIP_SIGN,
+               g_param_spec_boolean ("flip-sign",
+                                     P_("Flip Sign"),
+                                     P_("Flip sign of target value"),
+                                     FALSE,
+                                     GSF_PARAM_STATIC | G_PARAM_READWRITE));
+
        solver_signals[SOL_SIG_PREPARE] =
                g_signal_new ("prepare",
                              G_OBJECT_CLASS_TYPE (object_class),
@@ -2257,7 +2325,7 @@ cb_polish_iter (GnmSolverIterator *iter, GnmIterSolver *isol)
                        if (x[c] == xc)
                                break;
                        gnm_solver_set_vars (sol, x);
-                       y = gnm_iter_solver_get_target_value (isol);
+                       y = gnm_solver_get_target_value (sol);
 
                        if (y < isol->yk && gnm_solver_check_constraints (sol))  {
                                /* Success!  */
@@ -2422,17 +2490,17 @@ GSF_CLASS (GnmSolverIteratorCompound, gnm_solver_iterator_compound,
 
 static GObjectClass *gnm_iter_solver_parent_class;
 
-enum {
-       ISOL_PROP_0,
-       ISOL_PROP_FLIP_SIGN
-};
-
-gnm_float
-gnm_iter_solver_get_target_value (GnmIterSolver *isol)
+void
+gnm_iter_solver_set_iterator (GnmIterSolver *isol, GnmSolverIterator *iterator)
 {
-       GnmSolver *sol = GNM_SOLVER (isol);
-       gnm_float y = gnm_solver_get_target_value (sol);
-       return isol->flip_sign ? 0 - y : y;
+       GnmSolverIterator *old_iterator;
+
+       g_return_if_fail (GNM_IS_ITER_SOLVER (isol));
+
+       old_iterator = isol->iterator;
+       isol->iterator = iterator ? g_object_ref (iterator) : NULL;
+       if (old_iterator)
+               g_object_unref (old_iterator);
 }
 
 gboolean
@@ -2458,7 +2526,7 @@ got_it:
                GnmCell *cell = g_ptr_array_index (sol->input_cells, i);
                isol->xk[i] = value_get_as_float (cell->value);
        }
-       isol->yk = gnm_iter_solver_get_target_value (isol);
+       isol->yk = gnm_solver_get_target_value (sol);
 
        gnm_iter_solver_set_solution (isol);
 
@@ -2474,7 +2542,7 @@ gnm_iter_solver_set_solution (GnmIterSolver *isol)
        int i;
 
        result->quality = GNM_SOLVER_RESULT_FEASIBLE;
-       result->value = isol->flip_sign ? 0 - isol->yk : isol->yk;
+       result->value = sol->flip_sign ? 0 - isol->yk : isol->yk;
        result->solution = value_new_array_empty (sol->input_width,
                                                  sol->input_height);
        for (i = 0; i < n; i++) {
@@ -2535,40 +2603,6 @@ gnm_iter_solver_init (GnmIterSolver *isol)
 {
 }
 
-static void
-gnm_iter_solver_get_property (GObject *object, guint property_id,
-                             GValue *value, GParamSpec *pspec)
-{
-       GnmIterSolver *isol = (GnmIterSolver *)object;
-
-       switch (property_id) {
-       case ISOL_PROP_FLIP_SIGN:
-               g_value_set_boolean (value, isol->flip_sign);
-               break;
-
-       default:
-               G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
-               break;
-       }
-}
-
-static void
-gnm_iter_solver_set_property (GObject *object, guint property_id,
-                             GValue const *value, GParamSpec *pspec)
-{
-       GnmIterSolver *isol = (GnmIterSolver *)object;
-
-       switch (property_id) {
-       case ISOL_PROP_FLIP_SIGN:
-               isol->flip_sign = g_value_get_boolean (value);
-               break;
-
-       default:
-               G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
-               break;
-       }
-}
-
 static gint
 gnm_iter_solver_idle (gpointer data)
 {
@@ -2634,17 +2668,8 @@ gnm_iter_solver_class_init (GObjectClass *object_class)
        object_class->dispose = gnm_iter_solver_dispose;
        object_class->finalize = gnm_iter_solver_finalize;
        object_class->constructed = gnm_iter_solver_constructed;
-       object_class->set_property = gnm_iter_solver_set_property;
-       object_class->get_property = gnm_iter_solver_get_property;
        sclass->start = gnm_iter_solver_start;
        sclass->stop = gnm_iter_solver_stop;
-
-       g_object_class_install_property (object_class, ISOL_PROP_FLIP_SIGN,
-               g_param_spec_boolean ("flip-sign",
-                                     P_("Flip Sign"),
-                                     P_("Flip sign of target value"),
-                                     FALSE,
-                                     GSF_PARAM_STATIC | G_PARAM_READWRITE));
 }
 
 GSF_CLASS (GnmIterSolver, gnm_iter_solver,
diff --git a/src/tools/gnm-solver.h b/src/tools/gnm-solver.h
index f457c70..564f693 100644
--- a/src/tools/gnm-solver.h
+++ b/src/tools/gnm-solver.h
@@ -200,6 +200,7 @@ typedef struct {
        GnmSolverParameters *params;
        GnmSolverResult *result;
        double starttime, endtime;
+       gboolean flip_sign;
 
        /* Derived information */
        GnmCell *target;
@@ -255,6 +256,8 @@ gnm_float gnm_solver_get_target_value (GnmSolver *solver);
 void gnm_solver_set_var (GnmSolver *sol, int i, gnm_float x);
 void gnm_solver_set_vars (GnmSolver *sol, gnm_float const *xs);
 
+gnm_float *gnm_solver_compute_gradient (GnmSolver *sol, gnm_float const *xs);
+
 /* ------------------------------------------------------------------------- */
 /* Solver subclass for subprocesses. */
 
@@ -378,7 +381,6 @@ struct GnmIterSolver_ {
 
        /* Current point */
        gnm_float *xk, yk;
-       gboolean flip_sign;
 
        GnmSolverIterator *iterator;
 
@@ -394,7 +396,7 @@ typedef struct {
 
 GType gnm_iter_solver_get_type (void);
 
-gnm_float gnm_iter_solver_get_target_value (GnmIterSolver *isol);
+void gnm_iter_solver_set_iterator (GnmIterSolver *isol, GnmSolverIterator *iterator);
 
 gboolean gnm_iter_solver_get_initial_solution (GnmIterSolver *isol, GError **err);
 void gnm_iter_solver_set_solution (GnmIterSolver *isol);