Add ability for reverse iteration to tower code, and corresponding

[pspp] / src / math / linreg / linreg.c

diff --git a/src/math/linreg/linreg.c b/src/math/linreg/linreg.c
index 9224cc6bad9332769a8797b783719d235a2cbb82..558f6646fe33dde8e2ed19bcac22fd2614e76bb1 100644 (file)
--- a/src/math/linreg/linreg.c
+++ b/src/math/linreg/linreg.c
@@ -95,7 +95,7 @@ linreg_mean_std (gsl_vector_const_view v, double *mp, double *sp, double *ssp)
   The return value is the number of distinct variables found.
  */
 int
-pspp_linreg_get_vars (const void *c_, struct variable **v)
+pspp_linreg_get_vars (const void *c_, const struct variable **v)
 {
   const pspp_linreg_cache *c = c_;
   struct pspp_coeff *coef = NULL;
@@ -114,7 +114,7 @@ pspp_linreg_get_vars (const void *c_, struct variable **v)
   /*
      Start at c->coeff[1] to avoid the intercept.
    */
-  v[result] = (struct variable *) pspp_coeff_get_var (c->coeff[1], 0);
+  v[result] =  pspp_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++)
@@ -130,7 +130,7 @@ pspp_linreg_get_vars (const void *c_, struct variable **v)
        }
       if (i < 0 && result < c->n_coeffs)
        {
-         v[result] = (struct variable *) tmp;
+         v[result] = tmp;
          result++;
        }
     }
@@ -182,15 +182,18 @@ 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);
-  for (i = 0; i < c->n_coeffs; i++)
+  if (c != NULL)
     {
-      pspp_coeff_free (c->coeff[i]);
+      gsl_vector_free (c->indep_means);
+      gsl_vector_free (c->indep_std);
+      gsl_vector_free (c->ss_indeps);
+      gsl_matrix_free (c->cov);
+      for (i = 0; i < c->n_coeffs; i++)
+       {
+         pspp_coeff_free (c->coeff[i]);
+       }
+      free (c);
     }
-  free (c);
   return true;
 }