src/ports/postgres/modules/stats/test/anova_test.sql_in

/* -----------------------------------------------------------------------------
 * Test ANOVA.
 *
 * Example taken from:
 * http://www.itl.nist.gov/div898/handbook/prc/section4/prc433.htm
 * -------------------------------------------------------------------------- */

CREATE TABLE nist_anova_test (
    id SERIAL,
    resistance FLOAT8[]
);

COPY nist_anova_test(resistance) FROM stdin;
{6.9,8.3,8.0}
{5.4,6.8,10.5}
{5.8,7.8,8.1}
{4.6,9.2,6.9}
{4.0,6.5,9.3}
\.

CREATE TABLE one_way_anova_nist AS
SELECT (one_way_anova(level, value)).* FROM (
    SELECT level, resistance[level] AS value
    FROM
        nist_anova_test, (
        SELECT * FROM generate_series(1,3) level
    ) q
) q;

SELECT * FROM one_way_anova_nist;
SELECT assert(
    relative_error(statistic, 9.59) < 0.001 AND
    relative_error(sum_squares_between, 27.897) < 0.001 AND
    relative_error(sum_squares_within, 17.452) < 0.001 AND
    df_between = 2 AND
    df_within = 12 AND
    relative_error(mean_squares_between, 13.949) < 0.001 AND
    relative_error(mean_squares_within, 1.454) < 0.001,
    'One-way ANOVA: Wrong results'
) FROM one_way_anova_nist;