bartlett_test_fl()

The bartlett_test_fl() function is a user-defined tabular function that performs the Bartlett Test.

Syntax

T | invoke bartlett_test_fl()(data1, data2, test_statistic,p_value)

Parameters

Function definition

You can define the function by either embedding its code as a query-defined function, or creating it as a stored function in your database, as follows:

Query-defined

Define the function using the following let statement. No permissions are required.

let bartlett_test_fl = (tbl:(*), data1:string, data2:string, test_statistic:string, p_value:string)
{
    let kwargs = bag_pack('data1', data1, 'data2', data2, 'test_statistic', test_statistic, 'p_value', p_value);
    let code = ```if 1:
        from scipy import stats
        data1 = kargs["data1"]
        data2 = kargs["data2"]
        test_statistic = kargs["test_statistic"]
        p_value = kargs["p_value"]
        def func(row):
            statistics = stats.bartlett(row[data1], row[data2])
            return statistics[0], statistics[1]
        result = df
        result[[test_statistic, p_value]]  = df.apply(func, axis=1, result_type = "expand")
    ```;
    tbl
    | evaluate python(typeof(*), code, kwargs)
};
// Write your query to use the function here.

Stored

Define the stored function once using the following .create function. Database User permissions are required.

.create-or-alter function with (folder = "Packages\\Stats", docstring = "Bartlett Test")
bartlett_test_fl(tbl:(*), data1:string, data2:string, test_statistic:string, p_value:string)
{
    let kwargs = bag_pack('data1', data1, 'data2', data2, 'test_statistic', test_statistic, 'p_value', p_value);
    let code = ```if 1:
        from scipy import stats
        data1 = kargs["data1"]
        data2 = kargs["data2"]
        test_statistic = kargs["test_statistic"]
        p_value = kargs["p_value"]
        def func(row):
            statistics = stats.bartlett(row[data1], row[data2])
            return statistics[0], statistics[1]
        result = df
        result[[test_statistic, p_value]]  = df.apply(func, axis=1, result_type = "expand")
    ```;
    tbl
    | evaluate python(typeof(*), code, kwargs)
}

Example

The following example uses the invoke operator to run the function.

Query-defined

To use a query-defined function, invoke it after the embedded function definition.

let bartlett_test_fl = (tbl:(*), data1:string, data2:string, test_statistic:string, p_value:string)
{
    let kwargs = bag_pack('data1', data1, 'data2', data2, 'test_statistic', test_statistic, 'p_value', p_value);
    let code = ```if 1:
        from scipy import stats
        data1 = kargs["data1"]
        data2 = kargs["data2"]
        test_statistic = kargs["test_statistic"]
        p_value = kargs["p_value"]
        def func(row):
            statistics = stats.bartlett(row[data1], row[data2])
            return statistics[0], statistics[1]
        result = df
        result[[test_statistic, p_value]]  = df.apply(func, axis=1, result_type = "expand")
    ```;
    tbl
    | evaluate python(typeof(*), code, kwargs)
};
// Example query that uses the function
datatable(id:string, sample1:dynamic, sample2:dynamic) [
'Test #1', dynamic([23.64, 20.57, 20.42]), dynamic([27.1, 22.12, 33.56]),
'Test #2', dynamic([20.85, 21.89, 23.41]), dynamic([35.09, 30.02, 26.52]),
'Test #3', dynamic([20.13, 20.5, 21.7, 22.02]), dynamic([32.2, 32.79, 33.9, 34.22])
]
| extend test_stat= 0.0, p_val = 0.0
| invoke bartlett_test_fl('sample1', 'sample2', 'test_stat', 'p_val')

Stored

datatable(id:string, sample1:dynamic, sample2:dynamic) [
'Test #1', dynamic([23.64, 20.57, 20.42]), dynamic([27.1, 22.12, 33.56]),
'Test #2', dynamic([20.85, 21.89, 23.41]), dynamic([35.09, 30.02, 26.52]),
'Test #3', dynamic([20.13, 20.5, 21.7, 22.02]), dynamic([32.2, 32.79, 33.9, 34.22])
]
| extend test_stat= 0.0, p_val = 0.0
| invoke bartlett_test_fl('sample1', 'sample2', 'test_stat', 'p_val')

Output

| Test #3 | [20.13, 20.5, 21.7, 22.02] | [32.2, 32.79, 33.9, 34.22] | 0.0026985713829234454 | 0.958570306268548 |