test_normality :: Shapiro-Wilk test for normality

test-normality

Function: test_normality (x)

Shapiro-Wilk test for normality. Argument x is a list of numbers, and sample size must be greater than 2 and less or equal than 5000, otherwise, function test_normality signals an error message.

Reference:

[1] Algorithm AS R94, Applied Statistics (1995), vol.44, no.4, 547-551

The output of function test_normality is an inference_result Maxima object with the following results:

'statistic: value of the W statistic.

'p_value: p-value under normal assumption.

Examples:

Checks for the normality of a population, based on a sample of size 9.

(%i1) load("stats")$
(%i2) x:[12,15,17,38,42,10,23,35,28]$
(%i3) test_normality(x);
                       |      SHAPIRO - WILK TEST
                       |
(%o3)                  | statistic = .9251055695162436
                       |
                       |  p_value = .4361763918860381

SEE ALSO:

test-variance-ratio

test-means-difference

test-means-difference-varequal

test-normality