X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fmath%2Fmoments.c;h=40180f7b7ecdb461c46eaa31b42c1927835c7b66;hb=40c169c1409b0f16e6ee8f0ceaa0ce6937c90a5c;hp=084e6d8c8b22f24c469212fec682080c204da6d9;hpb=a9acce47d67e0ab35ce1690e4f1b1ac0121c2d78;p=pspp diff --git a/src/math/moments.c b/src/math/moments.c index 084e6d8c8b..40180f7b7e 100644 --- a/src/math/moments.c +++ b/src/math/moments.c @@ -1,5 +1,5 @@ /* PSPP - a program for statistical analysis. - Copyright (C) 1997-9, 2000 Free Software Foundation, Inc. + Copyright (C) 1997-9, 2000, 2010, 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 @@ -15,15 +15,18 @@ along with this program. If not, see . */ #include -#include "moments.h" + +#include "math/moments.h" + #include #include #include -#include -#include -#include -#include "xalloc.h" +#include "data/val-type.h" +#include "data/value.h" +#include "libpspp/misc.h" + +#include "gl/xalloc.h" #include "gettext.h" #define _(msgid) gettext (msgid) @@ -49,13 +52,13 @@ calc_moments (enum moment max_moment, /* From _SPSS Statistical Algorithms, 2nd ed., 0-918469-89-9, section "DESCRIPTIVES". */ - if (fabs (*variance) >= 1e-20) + if (fabs (s2) >= 1e-20) { if (max_moment >= MOMENT_SKEWNESS && skewness != NULL && w > 2.) { double s3 = s2 * sqrt (s2); double g1 = (w * d3) / ((w - 1.0) * (w - 2.0) * s3); - if (finite (g1)) + if (isfinite (g1)) *skewness = g1; } if (max_moment >= MOMENT_KURTOSIS && kurtosis != NULL && w > 3.) @@ -63,7 +66,7 @@ calc_moments (enum moment max_moment, double den = (w - 2.) * (w - 3.) * pow2 (s2); double g2 = (w * (w + 1) * d4 / (w - 1.) / den - 3. * pow2 (d2) / den); - if (finite (g2)) + if (isfinite (g2)) *kurtosis = g2; } } @@ -222,12 +225,8 @@ moments_calculate (const struct moments *m, } else { - /* After the second pass we can calculate any stat. We - don't support "online" computation during the second - pass, so As a simple self-check, the total weight for - the passes must agree. */ + /* After the second pass we can calculate any stat. */ assert (m->pass == 2); - assert (m->w1 == m->w2); if (m->w2 > 0.) { @@ -458,6 +457,13 @@ moments1_destroy (struct moments1 *m) free (m); } + +double +calc_semean (double var, double W) +{ + return sqrt (var / W); +} + /* Returns the standard error of the skewness for the given total weight W.