Move all command implementations into a single 'commands' directory.
[pspp] / src / language / commands / ks-one-sample.c
diff --git a/src/language/commands/ks-one-sample.c b/src/language/commands/ks-one-sample.c
new file mode 100644 (file)
index 0000000..f02b930
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+/* PSPP - a program for statistical analysis.
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+#include "language/commands/ks-one-sample.h"
+
+#include <gsl/gsl_cdf.h>
+#include <math.h>
+#include <stdlib.h>
+
+
+#include "math/sort.h"
+#include "data/case.h"
+#include "data/casereader.h"
+#include "data/dataset.h"
+#include "data/dictionary.h"
+#include "data/format.h"
+#include "data/value-labels.h"
+#include "data/variable.h"
+#include "language/commands/freq.h"
+#include "language/commands/npar.h"
+#include "libpspp/array.h"
+#include "libpspp/assertion.h"
+#include "libpspp/cast.h"
+#include "libpspp/compiler.h"
+#include "libpspp/hash-functions.h"
+#include "libpspp/message.h"
+#include "libpspp/misc.h"
+#include "output/pivot-table.h"
+
+#include "gl/xalloc.h"
+
+#include "gettext.h"
+#define N_(msgid) msgid
+#define _(msgid) gettext (msgid)
+
+
+/* The per test variable statistics */
+struct ks
+{
+  double obs_cc;
+
+  double test_min ;
+  double test_max;
+  double mu;
+  double sigma;
+
+  double diff_pos;
+  double diff_neg;
+
+  double ssq;
+  double sum;
+};
+
+typedef double theoretical (const struct ks *ks, double x);
+typedef theoretical *theoreticalfp;
+
+static double
+theoretical_uniform (const struct ks *ks, double x)
+{
+  return gsl_cdf_flat_P (x, ks->test_min, ks->test_max);
+}
+
+static double
+theoretical_normal (const struct ks *ks, double x)
+{
+  return gsl_cdf_gaussian_P (x - ks->mu, ks->sigma);
+}
+
+static double
+theoretical_poisson (const struct ks *ks, double x)
+{
+  return gsl_cdf_poisson_P (x, ks->mu);
+}
+
+static double
+theoretical_exponential (const struct ks *ks, double x)
+{
+  return gsl_cdf_exponential_P (x, 1/ks->mu);
+}
+
+
+static const  theoreticalfp theoreticalf[4] =
+{
+  theoretical_normal,
+  theoretical_uniform,
+  theoretical_poisson,
+  theoretical_exponential
+};
+
+/*
+   Return the assymptotic approximation to the significance of Z
+ */
+static double
+ks_asymp_sig (double z)
+{
+  if (z < 0.27)
+    return 1;
+
+  if (z >= 3.1)
+    return 0;
+
+  if (z < 1)
+    {
+      double q = exp (-1.233701 * pow (z, -2));
+      return 1 - 2.506628 * (q + pow (q, 9) + pow (q, 25))/ z ;
+    }
+  else
+    {
+      double q = exp (-2 * z * z);
+      return 2 * (q - pow (q, 4) + pow (q, 9) - pow (q, 16))/ z ;
+    }
+}
+
+static void show_results (const struct ks *, const struct ks_one_sample_test *,  const struct fmt_spec *);
+
+
+void
+ks_one_sample_execute (const struct dataset *ds,
+                      struct casereader *input,
+                      enum mv_class exclude,
+                      const struct npar_test *test,
+                      bool x UNUSED, double y UNUSED)
+{
+  const struct dictionary *dict = dataset_dict (ds);
+  const struct ks_one_sample_test *kst = UP_CAST (test, const struct ks_one_sample_test, parent.parent);
+  const struct one_sample_test *ost = &kst->parent;
+  struct ccase *c;
+  const struct fmt_spec *wfmt = dict_get_weight_format (dict);
+  bool warn = true;
+  int v;
+  struct casereader *r = casereader_clone (input);
+
+  struct ks *ks = XCALLOC (ost->n_vars,  struct ks);
+
+  for (v = 0; v < ost->n_vars; ++v)
+    {
+      ks[v].obs_cc = 0;
+      ks[v].test_min = DBL_MAX;
+      ks[v].test_max = -DBL_MAX;
+      ks[v].diff_pos = -DBL_MAX;
+      ks[v].diff_neg = DBL_MAX;
+      ks[v].sum = 0;
+      ks[v].ssq = 0;
+    }
+
+  for (; (c = casereader_read (r)) != NULL; case_unref (c))
+    {
+      const double weight = dict_get_case_weight (dict, c, &warn);
+
+      for (v = 0; v < ost->n_vars; ++v)
+       {
+         const struct variable *var = ost->vars[v];
+         const union value *val = case_data (c, var);
+
+         if (var_is_value_missing (var, val) & exclude)
+           continue;
+
+         minimize (&ks[v].test_min, val->f);
+         maximize (&ks[v].test_max, val->f);
+
+         ks[v].obs_cc += weight;
+         ks[v].sum += val->f;
+         ks[v].ssq += pow2 (val->f);
+       }
+    }
+  casereader_destroy (r);
+
+  for (v = 0; v < ost->n_vars; ++v)
+    {
+      const struct variable *var = ost->vars[v];
+      double cc = 0;
+      double prev_empirical = 0;
+
+      switch (kst->dist)
+       {
+       case KS_UNIFORM:
+         if (kst->p[0] != SYSMIS)
+           ks[v].test_min = kst->p[0];
+
+         if (kst->p[1] != SYSMIS)
+           ks[v].test_max = kst->p[1];
+         break;
+       case KS_NORMAL:
+         if (kst->p[0] != SYSMIS)
+           ks[v].mu = kst->p[0];
+         else
+           ks[v].mu = ks[v].sum / ks[v].obs_cc;
+
+         if (kst->p[1] != SYSMIS)
+           ks[v].sigma = kst->p[1];
+         else
+           {
+             ks[v].sigma = ks[v].ssq - pow2 (ks[v].sum) / ks[v].obs_cc;
+             ks[v].sigma /= ks[v].obs_cc - 1;
+             ks[v].sigma = sqrt (ks[v].sigma);
+           }
+
+         break;
+       case KS_POISSON:
+       case KS_EXPONENTIAL:
+         if (kst->p[0] != SYSMIS)
+           ks[v].mu = ks[v].sigma = kst->p[0];
+         else
+           ks[v].mu = ks[v].sigma = ks[v].sum / ks[v].obs_cc;
+         break;
+       default:
+         NOT_REACHED ();
+       }
+
+      r = sort_execute_1var (casereader_clone (input), var);
+      for (; (c = casereader_read (r)) != NULL; case_unref (c))
+       {
+         double theoretical, empirical;
+         double d, dp;
+         const double weight = dict_get_case_weight (dict, c, &warn);
+         const union value *val = case_data (c, var);
+
+         if (var_is_value_missing (var, val) & exclude)
+           continue;
+
+         cc += weight;
+
+         empirical = cc / ks[v].obs_cc;
+
+         theoretical = theoreticalf[kst->dist] (&ks[v], val->f);
+
+         d = empirical - theoretical;
+         dp = prev_empirical - theoretical;
+
+         if (d > 0)
+           maximize (&ks[v].diff_pos, d);
+         else
+           minimize (&ks[v].diff_neg, d);
+
+         if (dp > 0)
+           maximize (&ks[v].diff_pos, dp);
+         else
+           minimize (&ks[v].diff_neg, dp);
+
+         prev_empirical = empirical;
+       }
+
+      casereader_destroy (r);
+    }
+
+  show_results (ks, kst, wfmt);
+
+  free (ks);
+  casereader_destroy (input);
+}
+
+
+static void
+show_results (const struct ks *ks,
+             const struct ks_one_sample_test *kst,
+             const struct fmt_spec *wfmt)
+{
+  struct pivot_table *table = pivot_table_create (
+    N_("One-Sample Kolmogorov-Smirnov Test"));
+  pivot_table_set_weight_format (table, wfmt);
+
+  struct pivot_dimension *statistics = pivot_dimension_create (
+    table, PIVOT_AXIS_ROW, N_("Statistics"),
+    N_("N"), PIVOT_RC_COUNT);
+
+  switch (kst->dist)
+    {
+    case KS_UNIFORM:
+      pivot_category_create_group (statistics->root, N_("Uniform Parameters"),
+                                   N_("Minimum"), N_("Maximum"));
+      break;
+
+    case KS_NORMAL:
+      pivot_category_create_group (statistics->root, N_("Normal Parameters"),
+                                   N_("Mean"), N_("Std. Deviation"));
+      break;
+
+    case KS_POISSON:
+      pivot_category_create_group (statistics->root, N_("Poisson Parameters"),
+                                   N_("Lambda"));
+      break;
+
+    case KS_EXPONENTIAL:
+      pivot_category_create_group (statistics->root,
+                                   N_("Exponential Parameters"), N_("Scale"));
+      break;
+
+    default:
+      NOT_REACHED ();
+    }
+
+  pivot_category_create_group (
+    statistics->root, N_("Most Extreme Differences"),
+    N_("Absolute"), N_("Positive"), N_("Negative"));
+
+  pivot_category_create_leaves (
+    statistics->root, N_("Kolmogorov-Smirnov Z"),
+    _("Asymp. Sig. (2-tailed)"), PIVOT_RC_SIGNIFICANCE);
+
+  struct pivot_dimension *variables = pivot_dimension_create (
+    table, PIVOT_AXIS_COLUMN, N_("Variables"));
+
+  for (size_t i = 0; i < kst->parent.n_vars; ++i)
+    {
+      int col = pivot_category_create_leaf (
+        variables->root, pivot_value_new_variable (kst->parent.vars[i]));
+
+      double values[10];
+      size_t n = 0;
+
+      values[n++] = ks[i].obs_cc;
+
+      switch (kst->dist)
+       {
+       case KS_UNIFORM:
+          values[n++] = ks[i].test_min;
+          values[n++] = ks[i].test_max;
+         break;
+
+       case KS_NORMAL:
+          values[n++] = ks[i].mu;
+          values[n++] = ks[i].sigma;
+         break;
+
+       case KS_POISSON:
+       case KS_EXPONENTIAL:
+          values[n++] = ks[i].mu;
+         break;
+
+       default:
+         NOT_REACHED ();
+       }
+
+      double abs = ks[i].diff_pos;
+      maximize (&abs, -ks[i].diff_neg);
+
+      double z = sqrt (ks[i].obs_cc) * abs;
+
+      values[n++] = abs;
+      values[n++] = ks[i].diff_pos;
+      values[n++] = ks[i].diff_neg;
+      values[n++] = z;
+      values[n++] = ks_asymp_sig (z);
+
+      for (size_t j = 0; j < n; j++)
+        pivot_table_put2 (table, j, col, pivot_value_new_number (values[j]));
+    }
+
+  pivot_table_submit (table);
+}