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Diffstat (limited to 'contrib/statmath/statmath.c')
| -rw-r--r-- | contrib/statmath/statmath.c | 309 |
1 files changed, 0 insertions, 309 deletions
diff --git a/contrib/statmath/statmath.c b/contrib/statmath/statmath.c deleted file mode 100644 index 7832b35fb2f..00000000000 --- a/contrib/statmath/statmath.c +++ /dev/null @@ -1,309 +0,0 @@ -/* ---------- - * Module statmath - * - * statistical aggregates for average, variance and standard - * deviation. - * - * $Header: /cvsroot/pgsql/contrib/statmath/Attic/statmath.c,v 1.2 2000/07/04 14:37:32 wieck Exp $ - * - * Jan Wieck - * ---------- - */ - -#include <stdio.h> -#include <stdlib.h> -#include <math.h> -#include <errno.h> - -#include "postgres.h" -#include "utils/palloc.h" - - -/* ---------- - * Declarations - * - * statmath_stateval_in() Input function for state transition variable - * statmath_stateval_out() Output function for state transition variable - * statmath_collect() State transition function to collect items - * statmath_average_fin() Final function for average aggregate - * statmath_variance_fin() Final function for variance aggregate - * statmath_stddev_fin() Final function for deviation aggregate - * ---------- - */ - -float64 statmath_stateval_in(char *str); -char *statmath_stateval_out(float64 sval); - -float64 statmath_collect(float64 sval, float64 item); -float64 statmath_average_fin(float64 sval, int4 n); -float64 statmath_variance_fin(float64 sval, int4 n); -float64 statmath_stddev_fin(float64 sval, int4 n); - - -/* ---------- - * statmath_checkval - - * - * Bounds checking for float8 values in Postgres - * ---------- - */ -static void -statmath_checkval(double val) -{ - if (fabs(val) > DBL_MAX) - elog(ERROR, "statmath: overflow"); - if (val != 0.0 && fabs(val) < DBL_MIN) - elog(ERROR, "statmath: underflow"); -} - - -/* ---------- - * statmath_stateval_in - - * - * Input function for the state transition value data type. - * The input string are two float8's separated with a colon ':'. - * ---------- - */ -float64 -statmath_stateval_in(char *str) -{ - float64 retval; - double tmp; - char *cp1, *cp2; - - if (!str) - return (float64) NULL; - - /* - * Allocate space for the result - */ - retval = (float64) palloc(sizeof(float64data) * 2); - - /* - * Get the first number - */ - errno = 0; - tmp = strtod(str, &cp1); - if (*cp1 != ':' || errno == ERANGE) - elog(ERROR, "statmath: illegal input format '%s'", str); - statmath_checkval(tmp); - retval[0] = tmp; - - /* - * Get the second number - */ - tmp = strtod(++cp1, &cp2); - if (*cp2 != '\0' || errno == ERANGE) - elog(ERROR, "statmath: illegal input format '%s'", str); - statmath_checkval(tmp); - retval[1] = tmp; - - /* - * Return the internal binary format - */ - return retval; -} - - -/* ---------- - * statmath_stateval_out - - * - * Output function for the state transition value data type. - * ---------- - */ -char * -statmath_stateval_out(float64 sval) -{ - char buf[1024]; - double v1, v2; - - if (!sval) - return pstrdup("(null)"); - - /* - * Print the values in the external format and return - * the result in allocated space - */ - v1 = sval[0]; - v2 = sval[1]; - sprintf(buf, "%.*g:%.*g", DBL_DIG, v1, DBL_DIG, v2); - return pstrdup(buf); -} - - -/* ---------- - * statmath_collect - - * - * State transition function to collect data for the variance - * and standard deviation aggregates. - * The state transition variable holds 2 float8 values. The - * first is the sum of the items, the second the sum of the - * item quadratic products. - * ---------- - */ -float64 -statmath_collect(float64 sval, float64 item) -{ - float64 retval; - double tmp; - - if (!sval || !item) - return (float64) NULL; - - /* - * Allocate space for the result - */ - retval = (float64) palloc(sizeof(float64data) * 2); - - /* - * Compute the new values - */ - tmp = sval[0] + *item; - statmath_checkval(tmp); - retval[0] = tmp; - - tmp = sval[1] + *item * *item; - statmath_checkval(tmp); - retval[1] = tmp; - - /* - * Return the result - */ - return retval; -} - - -/* ---------- - * statmath_average_fin - - * - * Final computation function for the average aggregate. - * ---------- - */ -float64 -statmath_average_fin(float64 sum, int4 n) -{ - float64 retval; - double tmp; - - if (!sum) - return (float64) NULL; - - /* - * Allocate space for the result - */ - retval = (float64) palloc(sizeof(float64data)); - - /* - * Avoid division by zero if no items collected - */ - if (n == 0) - { - *retval = 0.0; - return retval; - } - - /* - * Compute the average - */ - tmp = *sum / (double)n; - statmath_checkval(tmp); - *retval = tmp; - - /* - * Return the result - */ - return retval; -} - - -/* ---------- - * statmath_variance_fin - - * - * Final computation function for the variance aggregate - * ---------- - */ -float64 -statmath_variance_fin(float64 sval, int4 n) -{ - float64 retval; - double avg; - double variance; - - if (!sval) - return (float64) NULL; - - /* - * Allocate space for the result - */ - retval = (float64) palloc(sizeof(float64data)); - - /* - * Avoid division by zero if less than 2 items collected - */ - if (n < 2) - { - *retval = 0.0; - return retval; - } - - /* - * Calculate the variance - */ - avg = sval[0] / (double)n; - variance = (sval[1] - sval[0] * avg) / ((double)n - 1.0); - - statmath_checkval(variance); - *retval = variance; - - /* - * Return the result - */ - return retval; -} - - -/* ---------- - * statmath_stateval_in - - * - * Input function for the state transition value data type - * ---------- - */ -float64 -statmath_stddev_fin(float64 sval, int4 n) -{ - float64 retval; - double avg; - double stddev; - - if (!sval) - return (float64) NULL; - - /* - * Allocate space for the result - */ - retval = (float64) palloc(sizeof(float64data)); - - /* - * Avoid division by zero if less than 2 items collected - */ - if (n < 2) - { - *retval = 0.0; - return retval; - } - - /* - * Calculate the standard deviation - */ - avg = sval[0] / (double)n; - stddev = sqrt((sval[1] - sval[0] * avg) / ((double)n - 1.0)); - - statmath_checkval(stddev); - *retval = stddev; - - /* - * Return the result - */ - return retval; -} - - |