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 = UP_CAST (s, struct np, parent.parent);
double rank = np->prev_cc + (c + 1) / 2.0;
maximize (&np->y_max, y);
minimize (&np->y_min, y);
- cp = case_create (casewriter_get_proto (np->writer));
+ 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;
np->prev_cc = cc;
}
+/* 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().
+
+ There is no function to produce the results, which appear in "struct np" for
+ passing directly to np_plot_create() or dnp_plot_create().
+
+ The caller must eventually destroy the returned structure, with
+ statistic_destroy(). */
struct np *
np_create (double n, double mean, double var)
{
- struct np *np = XZALLOC (struct np);
- struct order_stats *os = &np->parent;
- struct statistic *stat = &os->parent;
- struct caseproto *proto;
- int i;
-
- np->prev_cc = 0;
-
- np->n = n;
- np->mean = mean;
-
- np->stddev = sqrt (var);
-
- np->y_min = np->ns_min = np->dns_min = DBL_MAX;
- np->y_max = np->ns_max = np->dns_max = -DBL_MAX;
-
- proto = caseproto_create ();
- for (i = 0; i < n_NP_IDX; i++)
+ struct caseproto *proto = caseproto_create ();
+ for (size_t i = 0; i < n_NP_IDX; i++)
proto = caseproto_add_width (proto, 0);
- np->writer = autopaging_writer_create (proto);
+ struct casewriter *writer = autopaging_writer_create (proto);
caseproto_unref (proto);
- os->k = 0;
- stat->destroy = destroy;
- stat->accumulate = acc;
-
+ 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;
}