Fixed memory leak. Made coeff a linreg_coeff** for easier use.

[pspp-builds.git] / src / math / linreg / linreg.c

diff --git a/src/math/linreg/linreg.c b/src/math/linreg/linreg.c
index 3e299157691c938b578aa4e7d51ba1b8525f4fb9..51f77b882e0b35546a0b80bc9479bababdbdd1f5 100644 (file)
--- a/src/math/linreg/linreg.c
+++ b/src/math/linreg/linreg.c
@@ -88,6 +88,54 @@ linreg_mean_std (gsl_vector_const_view v, double *mp, double *sp, double *ssp)
   return GSL_SUCCESS;
 }
 
+/*
+  Set V to contain an array of pointers to the variables
+  used in the model. V must be at least C->N_COEFFS in length.
+  The return value is the number of distinct variables found.
+ */
+int
+pspp_linreg_get_vars (const void *c_, struct variable **v)
+{
+  const pspp_linreg_cache *c = c_;
+  struct pspp_linreg_coeff *coef = NULL;
+  const struct variable *tmp;
+  int i;
+  int result = 0;
+
+  /*
+     Make sure the caller doesn't try to sneak a variable
+     into V that is not in the model.
+   */
+  for (i = 0; i < c->n_coeffs; i++)
+    {
+      v[i] = NULL;
+    }
+  /*
+     Start at c->coeff[1] to avoid the intercept.
+   */
+  v[result] = (struct variable *) pspp_linreg_coeff_get_var (c->coeff[1], 0);
+  result = (v[result] == NULL) ? 0 : 1;
+
+  for (coef = c->coeff[2]; coef < c->coeff[c->n_coeffs]; coef++)
+    {
+      tmp = pspp_linreg_coeff_get_var (coef, 0);
+      assert (tmp != NULL);
+      /* Repeated variables are likely to bunch together, at the end
+         of the array. */
+      i = result - 1;
+      while (i >= 0 && (v[i]->index != tmp->index))
+       {
+         i--;
+       }
+      if (i < 0 && result < c->n_coeffs)
+       {
+         v[result] = (struct variable *) tmp;
+         result++;
+       }
+    }
+  return result;
+}
+
 /*
   Allocate a pspp_linreg_cache and return a pointer
   to it. n is the number of cases, p is the number of
@@ -104,10 +152,10 @@ pspp_linreg_cache_alloc (size_t n, size_t p)
   c->indep_std = gsl_vector_alloc (p);
   c->ssx = gsl_vector_alloc (p);       /* Sums of squares for the
                                           independent variables. 
-                                       */
+                                        */
   c->ss_indeps = gsl_vector_alloc (p); /* Sums of squares for the
                                           model parameters. 
-                                       */
+                                        */
   c->cov = gsl_matrix_alloc (p + 1, p + 1);    /* Covariance matrix. */
   c->n_obs = n;
   c->n_indeps = p;
@@ -116,19 +164,31 @@ pspp_linreg_cache_alloc (size_t n, size_t p)
    */
   c->method = PSPP_LINREG_SWEEP;
   c->predict = pspp_linreg_predict;
-  c->residual = pspp_linreg_residual;
+  c->residual = pspp_linreg_residual;  /* The procedure to compute my
+                                          residuals. */
+  c->get_vars = pspp_linreg_get_vars;  /* The procedure that returns
+                                          pointers to model
+                                          variables. */
+  c->resid = NULL;             /* The variable storing my residuals. */
+  c->pred = NULL;              /* The variable storing my predicted values. */
 
   return c;
 }
 
 bool
-pspp_linreg_cache_free (pspp_linreg_cache * c)
+pspp_linreg_cache_free (void *m)
 {
+  int i;
+
+  pspp_linreg_cache *c = m;
   gsl_vector_free (c->indep_means);
   gsl_vector_free (c->indep_std);
   gsl_vector_free (c->ss_indeps);
   gsl_matrix_free (c->cov);
-  pspp_linreg_coeff_free (c->coeff);
+  for (i = 0; i < c->n_coeffs; i++)
+    {
+      pspp_linreg_coeff_free (c->coeff[i]);
+    }
   free (c);
   return true;
 }
@@ -186,7 +246,7 @@ pspp_linreg (const gsl_vector * Y, const gsl_matrix * X,
   cache->dfe = cache->dft - cache->dfm;
   cache->n_coeffs = X->size2 + 1;      /* Adjust this later to allow for
                                           regression through the origin. 
-                                       */
+                                        */
   if (cache->method == PSPP_LINREG_SWEEP)
     {
       gsl_matrix *sw;
@@ -260,7 +320,7 @@ pspp_linreg (const gsl_vector * Y, const gsl_matrix * X,
       for (i = 0; i < cache->n_indeps; i++)
        {
          tmp = gsl_matrix_get (sw, i, cache->n_indeps);
-         cache->coeff[i + 1].estimate = tmp;
+         cache->coeff[i + 1]->estimate = tmp;
          m -= tmp * gsl_vector_get (cache->indep_means, i);
        }
       /*
@@ -296,7 +356,7 @@ pspp_linreg (const gsl_vector * Y, const gsl_matrix * X,
            }
          gsl_matrix_set (cache->cov, 0, 0, tmp);
 
-         cache->coeff[0].estimate = m;
+         cache->coeff[0]->estimate = m;
        }
       else
        {
@@ -331,7 +391,7 @@ pspp_linreg (const gsl_vector * Y, const gsl_matrix * X,
                                cache->cov, &(cache->sse), wk);
       for (i = 0; i < cache->n_coeffs; i++)
        {
-         cache->coeff[i].estimate = gsl_vector_get (param_estimates, i);
+         cache->coeff[i]->estimate = gsl_vector_get (param_estimates, i);
        }
       if (rc == GSL_SUCCESS)
        {