PEARのMath_Stats

php 技術メモ

PHPのPEARにはMath_Statsという統計パラメータを算出するクラスがあるのですが、
ちょっといれてみました。

pear install Math_Stats-beta


サンプル。
[php] <?php require_once('Math/Stats.php');

$s = new Math_Stats(); $s->setData(array(1,2,2,3,3,3,10,11));

print_r($s->calcFull());[/php]
結果。
[php] Array ( [min] => 1 [max] => 11 [sum] => 35 [sum2] => 257 [count] => 8 [mean] => 4.375 [median] => 3 [mode] => Array ( [0] => 3 )

[midrange] => 6
[geometric_mean] => 3.23111231885
[harmonic_mean] => 2.50712250712
[stdev] => 3.85217934607
[absdev] => 3.0625
[variance] => 14.8392857143
[range] => 10
[std_error_of_mean] => 1.36195106898
[skewness] => 0.865320806527
[kurtosis] => -1.22232257089
[coeff_of_variation] => 0.880498136244
[sample_central_moments] => Array
    (
        [1] => 0
        [2] => 12.984375
        [3] => 49.46484375
        [4] => 391.452392578
        [5] => 2223.73718262
    )

[sample_raw_moments] => Array
    (
        [1] => 4.375
        [2] => 32.125
        [3] => 303.625
        [4] => 3114.625
        [5] => 32730.625
    )

[frequency] => Array
    (
        [1] => 1
        [2] => 2
        [3] => 3
        [10] => 1
        [11] => 1
    )

[quartiles] => Array
    (
        [25] => 2
        [50] => 3
        [75] => 6.5
    )

[interquartile_range] => 4.5
[interquartile_mean] => 2.6
[quartile_deviation] => 2.25
[quartile_variation_coefficient] => 52.9411764706
[quartile_skewness_coefficient] => 0.555555555556

)[/php]
quartiles（分位数）が出るのが素敵。
訳わからんパラメータもあるけど。