+
+/*
+ Free the transformation. Free its linear model if this
+ transformation is the last one.
+ */
+static bool
+regression_trns_free (void *t_)
+{
+ bool result = true;
+ struct reg_trns *t = t_;
+
+ if (t->trns_id == t->n_trns)
+ {
+ result = pspp_linreg_cache_free (t->c);
+ }
+ free (t);
+
+ return result;
+}
+
+/*
+ Gets the predicted values.
+ */
+static int
+regression_trns_pred_proc (void *t_, struct ccase *c, int case_idx UNUSED)
+{
+ size_t i;
+ size_t n_vals;
+ struct reg_trns *trns = t_;
+ pspp_linreg_cache *model;
+ union value *output = NULL;
+ const union value **vals = NULL;
+ struct variable **vars = NULL;
+
+ assert (trns != NULL);
+ model = trns->c;
+ assert (model != NULL);
+ assert (model->depvar != NULL);
+ assert (model->pred != NULL);
+
+ vars = xnmalloc (model->n_coeffs, sizeof (*vars));
+ n_vals = (*model->get_vars) (model, vars);
+
+ vals = xnmalloc (n_vals, sizeof (*vals));
+ output = case_data_rw (c, model->pred->fv);
+ assert (output != NULL);
+
+ for (i = 0; i < n_vals; i++)
+ {
+ vals[i] = case_data (c, vars[i]->fv);
+ }
+ output->f = (*model->predict) ((const struct variable **) vars,
+ vals, model, n_vals);
+ free (vals);
+ free (vars);
+ return TRNS_CONTINUE;
+}
+
+/*
+ Gets the residuals.
+ */
+static int
+regression_trns_resid_proc (void *t_, struct ccase *c, int case_idx UNUSED)
+{
+ size_t i;
+ size_t n_vals;
+ struct reg_trns *trns = t_;
+ pspp_linreg_cache *model;
+ union value *output = NULL;
+ const union value **vals = NULL;
+ const union value *obs = NULL;
+ struct variable **vars = NULL;
+
+ assert (trns != NULL);
+ model = trns->c;
+ assert (model != NULL);
+ assert (model->depvar != NULL);
+ assert (model->resid != NULL);
+
+ vars = xnmalloc (model->n_coeffs, sizeof (*vars));
+ n_vals = (*model->get_vars) (model, vars);
+
+ vals = xnmalloc (n_vals, sizeof (*vals));
+ output = case_data_rw (c, model->resid->fv);
+ assert (output != NULL);
+
+ for (i = 0; i < n_vals; i++)
+ {
+ vals[i] = case_data (c, vars[i]->fv);
+ }
+ obs = case_data (c, model->depvar->fv);
+ output->f = (*model->residual) ((const struct variable **) vars,
+ vals, obs, model, n_vals);
+ free (vals);
+ free (vars);
+ return TRNS_CONTINUE;
+}
+
+/*
+ Returns 0 if NAME is a duplicate of any existing variable name.
+*/
+static int
+try_name (char *name)
+{
+ if (dict_lookup_var (default_dict, name) != NULL)
+ return 0;
+
+ return 1;
+}
+static void
+reg_get_name (char name[LONG_NAME_LEN], const char prefix[LONG_NAME_LEN])
+{
+ int i = 1;
+
+ snprintf (name, LONG_NAME_LEN, "%s%d", prefix, i);
+ while (!try_name (name))
+ {
+ i++;
+ snprintf (name, LONG_NAME_LEN, "%s%d", prefix, i);
+ }
+}
+static void
+reg_save_var (const char *prefix, trns_proc_func * f,
+ pspp_linreg_cache * c, struct variable **v, int n_trns)
+{
+ static int trns_index = 1;
+ char name[LONG_NAME_LEN];
+ struct variable *new_var;
+ struct reg_trns *t = NULL;
+
+ t = xmalloc (sizeof (*t));
+ t->trns_id = trns_index;
+ t->n_trns = n_trns;
+ t->c = c;
+ reg_get_name (name, prefix);
+ new_var = dict_create_var (default_dict, name, 0);
+ assert (new_var != NULL);
+ *v = new_var;
+ add_transformation (f, regression_trns_free, t);
+ trns_index++;
+}