X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fmath%2Fcovariance.c;h=446ee6621a1e11881c37e5dba04d8d645c1610a8;hb=81579d9e9f994fb2908f50af41c3eb033d216e58;hp=d60d609e45681ffc7858abb83490b0b07b09fb46;hpb=a741cf4e8348e478ec5e8658cebeb80dc0376b1a;p=pspp-builds.git diff --git a/src/math/covariance.c b/src/math/covariance.c index d60d609e..446ee662 100644 --- a/src/math/covariance.c +++ b/src/math/covariance.c @@ -1,5 +1,5 @@ /* PSPP - a program for statistical analysis. - Copyright (C) 2009 Free Software Foundation, Inc. + Copyright (C) 2009, 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 @@ -16,15 +16,18 @@ #include -#include -#include "covariance.h" -#include -#include "moments.h" +#include "math/covariance.h" + #include -#include -#include -#include -#include "categoricals.h" + +#include "data/case.h" +#include "data/variable.h" +#include "libpspp/assertion.h" +#include "libpspp/misc.h" +#include "math/categoricals.h" +#include "math/moments.h" + +#include "gl/xalloc.h" #define n_MOMENTS (MOMENT_VARIANCE + 1) @@ -68,7 +71,7 @@ struct covariance { /* The variables for which the covariance matrix is to be calculated. */ size_t n_vars; - const struct variable **vars; + const struct variable *const *vars; /* Categorical variables. */ struct categoricals *categoricals; @@ -131,11 +134,11 @@ covariance_moments (const struct covariance *cov, int m) /* Create a covariance struct. */ struct covariance * -covariance_1pass_create (size_t n_vars, const struct variable **vars, +covariance_1pass_create (size_t n_vars, const struct variable *const *vars, const struct variable *weight, enum mv_class exclude) { size_t i; - struct covariance *cov = xmalloc (sizeof *cov); + struct covariance *cov = xzalloc (sizeof *cov); cov->passes = 1; cov->state = 0; @@ -156,7 +159,9 @@ covariance_1pass_create (size_t n_vars, const struct variable **vars, cov->n_cm = (n_vars * (n_vars - 1) ) / 2; - cov->cm = xcalloc (sizeof *cov->cm, cov->n_cm); + if (cov->n_cm > 0) + cov->cm = xcalloc (sizeof *cov->cm, cov->n_cm); + cov->categoricals = NULL; return cov; } @@ -168,8 +173,8 @@ covariance_1pass_create (size_t n_vars, const struct variable **vars, until then. */ struct covariance * -covariance_2pass_create (size_t n_vars, const struct variable **vars, - size_t n_catvars, const struct variable **catvars, +covariance_2pass_create (size_t n_vars, const struct variable *const *vars, + struct categoricals *cats, const struct variable *wv, enum mv_class exclude) { size_t i; @@ -195,7 +200,7 @@ covariance_2pass_create (size_t n_vars, const struct variable **vars, cov->n_cm = -1; cov->cm = NULL; - cov->categoricals = categoricals_create (catvars, n_catvars, wv, exclude); + cov->categoricals = cats; return cov; } @@ -265,6 +270,7 @@ get_val (const struct covariance *cov, int i, const struct ccase *c) return categoricals_get_binary_by_subscript (cov->categoricals, i - cov->n_vars, c); } +#if 0 void dump_matrix (const gsl_matrix *m) { @@ -277,6 +283,7 @@ dump_matrix (const gsl_matrix *m) printf ("\n"); } } +#endif /* Call this function for every case in the data set */ void @@ -292,7 +299,8 @@ covariance_accumulate_pass1 (struct covariance *cov, const struct ccase *c) cov->state = 1; } - categoricals_update (cov->categoricals, c); + if (cov->categoricals) + categoricals_update (cov->categoricals, c); for (i = 0 ; i < cov->dim; ++i) { @@ -338,8 +346,11 @@ covariance_accumulate_pass2 (struct covariance *cov, const struct ccase *c) assert (cov->state == 1); cov->state = 2; - cov->dim = cov->n_vars + - categoricals_total (cov->categoricals) - categoricals_get_n_variables (cov->categoricals); + cov->dim = cov->n_vars; + + if (cov->categoricals) + cov->dim += categoricals_total (cov->categoricals) + - categoricals_get_n_variables (cov->categoricals); cov->n_cm = (cov->dim * (cov->dim - 1) ) / 2; cov->cm = xcalloc (sizeof *cov->cm, cov->n_cm); @@ -351,7 +362,8 @@ covariance_accumulate_pass2 (struct covariance *cov, const struct ccase *c) cov->moments[i] = resize_matrix (cov->moments[i], cov->dim); } - categoricals_done (cov->categoricals); + if (cov->categoricals) + categoricals_done (cov->categoricals); /* Populate the moments matrices with the categorical value elements */ for (i = cov->n_vars; i < cov->dim; ++i) @@ -520,7 +532,7 @@ cm_to_gsl (struct covariance *cov) } -static const gsl_matrix * +static gsl_matrix * covariance_calculate_double_pass (struct covariance *cov) { size_t i, j; @@ -544,7 +556,7 @@ covariance_calculate_double_pass (struct covariance *cov) return cm_to_gsl (cov); } -static const gsl_matrix * +static gsl_matrix * covariance_calculate_single_pass (struct covariance *cov) { size_t i, j; @@ -589,16 +601,16 @@ covariance_calculate_single_pass (struct covariance *cov) } +/* Return a pointer to gsl_matrix containing the pairwise covariances. The + caller owns the returned matrix and must free it when it is no longer + needed. -/* - Return a pointer to gsl_matrix containing the pairwise covariances. - The matrix remains owned by the COV object, and must not be freed. - Call this function only after all data have been accumulated. -*/ -const gsl_matrix * + Call this function only after all data have been accumulated. */ +gsl_matrix * covariance_calculate (struct covariance *cov) { - assert ( cov->state > 0 ); + if ( cov->state <= 0 ) + return NULL; switch (cov->passes) { @@ -613,7 +625,95 @@ covariance_calculate (struct covariance *cov) } } +/* + Covariance computed without dividing by the sample size. + */ +static gsl_matrix * +covariance_calculate_double_pass_unnormalized (struct covariance *cov) +{ + size_t i, j; + for (i = 0 ; i < cov->dim; ++i) + { + for (j = 0 ; j < cov->dim; ++j) + { + int idx; + double *x = gsl_matrix_ptr (cov->moments[MOMENT_VARIANCE], i, j); + + idx = cm_idx (cov, i, j); + if ( idx >= 0) + { + x = &cov->cm [idx]; + } + } + } + + return cm_to_gsl (cov); +} + +static gsl_matrix * +covariance_calculate_single_pass_unnormalized (struct covariance *cov) +{ + size_t i, j; + + for (i = 0 ; i < cov->dim; ++i) + { + for (j = 0 ; j < cov->dim; ++j) + { + double *x = gsl_matrix_ptr (cov->moments[MOMENT_VARIANCE], i, j); + *x -= pow2 (gsl_matrix_get (cov->moments[MOMENT_MEAN], i, j)) + / gsl_matrix_get (cov->moments[MOMENT_NONE], i, j); + } + } + for ( j = 0 ; j < cov->dim - 1; ++j) + { + for (i = j + 1 ; i < cov->dim; ++i) + { + double *x = &cov->cm [cm_idx (cov, i, j)]; + + *x -= + gsl_matrix_get (cov->moments[MOMENT_MEAN], i, j) + * + gsl_matrix_get (cov->moments[MOMENT_MEAN], j, i) + / gsl_matrix_get (cov->moments[MOMENT_NONE], i, j); + } + } + + return cm_to_gsl (cov); +} + +/* Return a pointer to gsl_matrix containing the pairwise covariances. The + caller owns the returned matrix and must free it when it is no longer + needed. + + Call this function only after all data have been accumulated. */ +gsl_matrix * +covariance_calculate_unnormalized (struct covariance *cov) +{ + if ( cov->state <= 0 ) + return NULL; + + switch (cov->passes) + { + case 1: + return covariance_calculate_single_pass_unnormalized (cov); + break; + case 2: + return covariance_calculate_double_pass_unnormalized (cov); + break; + default: + NOT_REACHED (); + } +} + +/* Function to access the categoricals used by COV + The return value is owned by the COV +*/ +const struct categoricals * +covariance_get_categoricals (const struct covariance *cov) +{ + return cov->categoricals; +} /* Destroy the COV object */ @@ -621,7 +721,7 @@ void covariance_destroy (struct covariance *cov) { size_t i; - free (cov->vars); + categoricals_destroy (cov->categoricals); for (i = 0; i < n_MOMENTS; ++i)