#include "gl/xalloc.h"
-#include "gettext.h"
-#define _(msgid) gettext (msgid)
-#define N_(msgid) msgid
-
-const char *const ptile_alg_desc[] = {
- "",
- N_("HAverage"),
- N_("Weighted Average"),
- N_("Rounded"),
- N_("Empirical"),
- N_("Empirical with averaging")
-};
-
-
-
+/* Return the value of the percentile. */
double
percentile_calculate (const struct percentile *ptl, enum pc_alg alg)
{
struct percentile *mutable = CONST_CAST (struct percentile *, ptl);
const struct order_stats *os = &ptl->parent;
- if ( ptl->g1 == SYSMIS)
+ if (ptl->g1 == SYSMIS)
mutable->g1 = (os->k[0].tc - os->k[0].cc) / os->k[0].c_p1;
- if ( ptl->g1_star == SYSMIS)
+ if (ptl->g1_star == SYSMIS)
mutable->g1_star = os->k[0].tc - os->k[0].cc;
- if ( ptl->g2 == SYSMIS)
+ if (ptl->g2 == SYSMIS)
{
- if ( os->k[1].c == 0 )
+ if (os->k[1].c == 0)
mutable->g2 = os->k[1].tc / os->k[1].c_p1;
- else if ( os->k[1].c_p1 == 0 )
+ else if (os->k[1].c_p1 == 0)
mutable->g2 = 0;
else
mutable->g2 = (os->k[1].tc - os->k[1].cc) / os->k[1].c_p1;
}
- if ( ptl->g2_star == SYSMIS)
+ if (ptl->g2_star == SYSMIS)
{
- if ( os->k[1].c == 0 )
+ if (os->k[1].c == 0)
mutable->g2_star = os->k[1].tc;
- else if ( os->k[1].c_p1 == 0 )
+ else if (os->k[1].c_p1 == 0)
mutable->g2_star = 0;
else
mutable->g2_star = os->k[1].tc - os->k[1].cc;
switch (alg)
{
case PC_WAVERAGE:
- if ( ptl->g1_star >= 1.0)
+ if (ptl->g1_star >= 1.0)
return os->k[0].y_p1;
else
{
- double a = ( os->k[0].y == SYSMIS ) ? 0 : os->k[0].y;
+ double a = (os->k[0].y == SYSMIS) ? 0 : os->k[0].y;
if (os->k[0].c_p1 >= 1.0)
return (1 - ptl->g1_star) * a + ptl->g1_star * os->k[0].y_p1;
case PC_ROUND:
{
- double a = ( os->k[0].y == SYSMIS ) ? 0 : os->k[0].y;
+ double a = (os->k[0].y == SYSMIS) ? 0 : os->k[0].y;
if (os->k[0].c_p1 >= 1.0)
return (ptl->g1_star < 0.5) ? a : os->k[0].y_p1;
break;
case PC_EMPIRICAL:
- if ( ptl->g1_star == 0 )
+ if (ptl->g1_star == 0)
return os->k[0].y;
else
return os->k[0].y_p1;
break;
case PC_HAVERAGE:
- if ( ptl->g2_star >= 1.0)
+ if (ptl->g2_star >= 1.0)
{
return os->k[1].y_p1;
}
else
{
- double a = ( os->k[1].y == SYSMIS ) ? 0 : os->k[1].y;
+ double a = (os->k[1].y == SYSMIS) ? 0 : os->k[1].y;
- if ( os->k[1].c_p1 >= 1.0)
+ if (os->k[1].c_p1 >= 1.0)
{
- if ( ptl->g2_star == 0)
+ if (ptl->g2_star == 0)
return os->k[1].y;
return (1 - ptl->g2_star) * a + ptl->g2_star * os->k[1].y_p1;
break;
case PC_AEMPIRICAL:
- if ( ptl->g1_star == 0 )
+ if (ptl->g1_star == 0)
return (os->k[0].y + os->k[0].y_p1)/ 2.0;
else
return os->k[0].y_p1;
destroy (struct statistic *stat)
{
struct percentile *ptl = UP_CAST (stat, struct percentile, parent.parent);
- struct order_stats *os = &ptl->parent;
- free (os->k);
free (ptl);
}
-
+/* Create the Pth percentile.
+ W is the total sum of weights in the data set.
+*/
struct percentile *
percentile_create (double p, double W)
{
- struct percentile *ptl = xzalloc (sizeof (*ptl));
- struct order_stats *os = &ptl->parent;
- struct statistic *stat = &os->parent;
-
assert (p >= 0);
assert (p <= 1.0);
- ptl->ptile = p;
- ptl->w = W;
-
- os->n_k = 2;
- os->k = xcalloc (2, sizeof (*os->k));
- os->k[0].tc = W * p;
- os->k[1].tc = (W + 1.0) * p;
-
- ptl->g1 = ptl->g1_star = SYSMIS;
- ptl->g2 = ptl->g2_star = SYSMIS;
-
- os->k[1].y_p1 = os->k[1].y = SYSMIS;
- os->k[0].y_p1 = os->k[0].y = SYSMIS;
-
- stat->destroy = destroy;
-
+ struct percentile *ptl = xmalloc (sizeof *ptl);
+ *ptl = (struct percentile) {
+ .parent = {
+ .parent = {
+ .destroy = destroy
+ },
+ .k = ptl->k,
+ .n_k = 2,
+ },
+ .ptile = p,
+ .w = W,
+ .g1 = SYSMIS,
+ .g1_star = SYSMIS,
+ .g2 = SYSMIS,
+ .g2_star = SYSMIS,
+ .k[0] = { .tc = W * p, .y = SYSMIS, .y_p1 = SYSMIS },
+ .k[1] = { .tc = (W + 1.0) * p, .y = SYSMIS, .y_p1 = SYSMIS },
+ };
return ptl;
}
-