/* PSPP - a program for statistical analysis.
- Copyright (C) 2008 Free Software Foundation, Inc.
+ Copyright (C) 2008, 2009, 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
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
-#include "np.h"
-#include <math/moments.h>
-#include <gl/xalloc.h>
-#include <stdlib.h>
-#include <math.h>
+
+#include "math/np.h"
+
#include <gsl/gsl_cdf.h>
-#include <libpspp/compiler.h>
-#include <data/case.h>
-#include <data/casewriter.h>
+#include <math.h>
+#include <stdlib.h>
+
+#include "data/case.h"
+#include "data/casewriter.h"
+#include "libpspp/cast.h"
+#include "libpspp/compiler.h"
+#include "libpspp/misc.h"
+#include "math/moments.h"
+
+#include "gl/xalloc.h"
static void
destroy (struct statistic *stat)
{
- struct order_stats *os = (struct order_stats *) stat;
- free (os);
+ struct np *np = UP_CAST (stat, struct np, parent.parent);
+ free (np);
}
-
static void
acc (struct statistic *s, const struct ccase *cx UNUSED,
double c, double cc, double y)
{
- struct ccase cp;
- struct np *np = (struct np *) s;
+ struct np *np = UP_CAST (s, struct np, parent.parent);
double rank = np->prev_cc + (c + 1) / 2.0;
- double ns = gsl_cdf_ugaussian_Pinv (rank / ( np->n + 1 ));
+ double ns = gsl_cdf_ugaussian_Pinv (rank / (np->n + 1));
double z = (y - np->mean) / np->stddev;
maximize (&np->y_max, y);
minimize (&np->y_min, y);
- case_create (&cp, n_NP_IDX);
-
- case_data_rw_idx (&cp, NP_IDX_Y)->f = y;
- case_data_rw_idx (&cp, NP_IDX_NS)->f = ns;
- case_data_rw_idx (&cp, NP_IDX_DNS)->f = dns;
-
- casewriter_write (np->writer, &cp);
+ struct ccase *cp = case_create (casewriter_get_proto (np->writer));
+ *case_num_rw_idx (cp, NP_IDX_Y) = y;
+ *case_num_rw_idx (cp, NP_IDX_NS) = ns;
+ *case_num_rw_idx (cp, NP_IDX_DNS) = dns;
+ casewriter_write (np->writer, cp);
np->prev_cc = cc;
}
-struct order_stats *
-np_create (const struct moments1 *m)
-{
- double variance;
- struct np *np = xzalloc (sizeof (*np));
- struct statistic *stat = (struct statistic *) np;
- struct order_stats *os = (struct order_stats *) np;
-
- np->prev_cc = 0;
-
- moments1_calculate (m, &np->n, &np->mean, &variance, NULL, NULL);
+/* Creates and returns a data structure whose accumulated results can be used
+ to produce a normal probability plot. The caller must supply the weighted
+ sample size N and the mean MEAN and variance VAR of the distribution, then
+ feed in the data with order_stats_accumulate() or
+ order_stats_accumulate_idx().
- np->stddev = sqrt (variance);
+ There is no function to produce the results, which appear in "struct np" for
+ passing directly to np_plot_create() or dnp_plot_create().
- np->y_min = np->ns_min = np->dns_min = DBL_MAX;
- np->y_max = np->ns_max = np->dns_max = -DBL_MAX;
-
- np->writer = autopaging_writer_create (n_NP_IDX);
-
- os->k = 0;
- stat->destroy = destroy;
- stat->accumulate = acc;
-
- return os;
+ The caller must eventually destroy the returned structure, with
+ statistic_destroy(). */
+struct np *
+np_create (double n, double mean, double var)
+{
+ struct caseproto *proto = caseproto_create ();
+ for (size_t i = 0; i < n_NP_IDX; i++)
+ proto = caseproto_add_width (proto, 0);
+ struct casewriter *writer = autopaging_writer_create (proto);
+ caseproto_unref (proto);
+
+ struct np *np = xmalloc (sizeof *np);
+ *np = (struct np) {
+ .parent = {
+ .parent = {
+ .destroy = destroy,
+ },
+ .accumulate = acc,
+ },
+ .n = n,
+ .mean = mean,
+ .stddev = sqrt (var),
+ .ns_min = DBL_MAX,
+ .ns_max = -DBL_MAX,
+ .dns_min = DBL_MAX,
+ .dns_max = -DBL_MAX,
+ .y_min = DBL_MAX,
+ .y_max = -DBL_MAX,
+ .writer = writer,
+ };
+ return np;
}