ClickHouse/docs/en/sql-reference/aggregate-functions/reference/studentttest.md
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DOCSUP-3908: mannWitneyUTest, welchTTest and studentTTest documentation (#19784)
* studentTTest function description

* welchttest description, links in studentttest

* mannWhitneyUTest description

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* Text changed slightly

* Text changed slightly

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* - First header is first level.
- sample_index type set to UInt64.
- Return values renamed.

- mannWhitneyUTest:
  - added continuity_correction parameter
  - optional parameters wrapped in braces [ ]
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* Improved formulations (hopefully)
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* Russian function description

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* Translated 'Original article' to russian

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* fixed alowed parameter value: "two sided" -> "two-sided"
* duplicate word "require" is removed from exception messages

* mannWhitneyUTest description changed
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Co-authored-by: Alexey Smirnov <alexey-sm@yandex-team.ru>
2021-02-08 15:58:27 +03:00

2.1 KiB

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300 studentTTest

studentTTest

Applies Student's t-test to samples from two populations.

Syntax

studentTTest(sample_data, sample_index)

Values of both samples are in the sample_data column. If sample_index equals to 0 then the value in that row belongs to the sample from the first population. Otherwise it belongs to the sample from the second population. The null hypothesis is that means of populations are equal. Normal distribution with equal variances is assumed.

Parameters

Returned values

Tuple with two elements:

Example

Input table:

┌─sample_data─┬─sample_index─┐
│        20.3 │            0 │
│        21.1 │            0 │
│        21.9 │            1 │
│        21.7 │            0 │
│        19.9 │            1 │
│        21.8 │            1 │
└─────────────┴──────────────┘

Query:

SELECT studentTTest(sample_data, sample_index) FROM student_ttest;

Result:

┌─studentTTest(sample_data, sample_index)───┐
│ (-0.21739130434783777,0.8385421208415731) │
└───────────────────────────────────────────┘

See Also

Original article