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README.statmath | ||
statmath.c | ||
statmath.sql.in |
Statistical aggregate functions for PostgreSQL. This module provides some aggregate functions for statistical mathematics. A new datatype holding two double precision floating point values is required by them. The aggregates are: average(float8) average value computed by n ___ _ 1 \ x = --- > x n /__ i i=1 variance(float8 variance computed by n ___ 2 1 \ _ 2 s = --- > (x - x) n-1 /__ i i=1 stddev(float8) standard deviation computed by _____ / 2 s = / s \/ -- Jan Wieck <JanWieck@Yahoo.com>