This toolbox provides elementary tests for the evaluation data which were
generated by natural scientists and engineers in the first place. These data
have to be normal distributed. SampleSTAT is focused on small sample sizes but
offers routines for bigger distributions (>30 values), too.
It offers functions for calculates the range of dispersion of the values and the
mean regarding a given statistical confidence level. Furthermore it provides
tests on outliers and a method to test the data for normality.
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FUNCTIONS - Measures of Variation:
Gives you more information of your data as the standard deviation (S.D.) can
do with just 68% confidence. These tests provide confidence level of 95%, 99%
and 99.9% and calculate the range of dispersion not only for values but for
the mean, too. It extends the internal functions: mean, stdev, median.
* ST_strayarea:
Calculates the stray area (range of dispersion of the values)
* ST_trustarea:
Calculates the trust area (range of dispersion of the mean or S.D. of the
mean)
* ST_studentfactor:
Determines the student factor for an amount of numbers, service
function for ST_strayarea and ST_trustarea
FUNCTIONS - Tests on Outliers
It is not always easy to distinguish whether a value is a valid part of a sample
distribution or not. These outlier tests provide quick hints.
* ST_deandixon:
Dean-Dixon outlier test for small sample sizes (<30)
* ST_pearsonhartley:
Pearson-Hartley outlier test for bigger sample sizes (>30)
* ST_nalimov:
Nalimov test for small and larger sample sizes
* ST_outlier:
Basic and often used tests for medium to large sample sizes, based
on S.D. (standard deviation) or IQR (inter-quartile range)
FUNCTIONS - Distribution Tests
All routines above rely on a normal distributed data. To test for normality
a powerful test is provided.
* ST_shapirowilk:
Shapiro-Wilk test for normality is powerful even on small
sample sizes.
* ST_ivplot:
Very basic individual value plot (EXPERIMENTAL)
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CHANGELOG:
2.0.0 - Outlier tests (Dean-Dixon, Pearson-Hartley, Nalimov) and
a basic test added
- Distribution tests (Shapiro-Wilk) added
- Individual Value Plot added (EXPERIMENTAL)
LITERATURE:
* R. Kaiser, G. Gottschalk; "Elementare Tests zur
Beurteilung von Meßdaten", BI Hochschultaschenbücher, Bd. 774,
Mannheim 1972.
* Lohringer, H., "Grundlagen der Statistik", Oct, 10th,
2012,
http://www.statistics4u.info/
* Shapiro, Wilk: "An Analysis of Variance Test for Normality",
Biometrika, Vol. 52, No. 3/4. (Dec., 1965), pp. 591-611.
