binomial_test_fl()

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Applies to: ✅ Azure Data Explorer

The function binomial_test_fl() is a UDF (user-defined function) that performs the binomial test.

Prerequisites

  • The Python plugin must be enabled on the cluster. This is required for the inline Python used in the function.

Syntax

T | invoke binomial_test_fl(successes, trials [,success_prob [, alt_hypotheis ]])

Learn more about syntax conventions.

Parameters

Name Type Required Description
successes string ✔️ The name of the column containing the number of success results.
trials string ✔️ The name of the column containing the total number of trials.
p_value string ✔️ The name of the column to store the results.
success_prob real The success probability. The default is 0.5.
alt_hypotheis string The alternate hypothesis can be two-sided, greater, or less. The default is two-sided.

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:

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

Important

A let statement can't run on its own. It must be followed by a tabular expression statement. To run a working example of binomial_test_fl(), see Example.

let binomial_test_fl = (tbl:(*), successes:string, trials:string, p_value:string, success_prob:real=0.5, alt_hypotheis:string='two-sided')
{
    let kwargs = bag_pack('successes', successes, 'trials', trials, 'p_value', p_value, 'success_prob', success_prob, 'alt_hypotheis', alt_hypotheis);
    let code = ```if 1:
        from scipy import stats
        
        successes = kargs["successes"]
        trials = kargs["trials"]
        p_value = kargs["p_value"]
        success_prob = kargs["success_prob"]
        alt_hypotheis = kargs["alt_hypotheis"]
        
        def func(row, prob, h1):
            pv = stats.binom_test(row[successes], row[trials], p=prob, alternative=h1)
            return pv
        result = df
        result[p_value] = df.apply(func, axis=1, args=(success_prob, alt_hypotheis), result_type="expand")
    ```;
    tbl
    | evaluate python(typeof(*), code, kwargs)
};
// Write your query to use the function here.

Example

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

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

let binomial_test_fl = (tbl:(*), successes:string, trials:string, p_value:string, success_prob:real=0.5, alt_hypotheis:string='two-sided')
{
    let kwargs = bag_pack('successes', successes, 'trials', trials, 'p_value', p_value, 'success_prob', success_prob, 'alt_hypotheis', alt_hypotheis);
    let code = ```if 1:
        from scipy import stats
        
        successes = kargs["successes"]
        trials = kargs["trials"]
        p_value = kargs["p_value"]
        success_prob = kargs["success_prob"]
        alt_hypotheis = kargs["alt_hypotheis"]
        
        def func(row, prob, h1):
            pv = stats.binom_test(row[successes], row[trials], p=prob, alternative=h1)
            return pv
        result = df
        result[p_value] = df.apply(func, axis=1, args=(success_prob, alt_hypotheis), result_type="expand")
    ```;
    tbl
    | evaluate python(typeof(*), code, kwargs)
};
datatable(id:string, x:int, n:int) [
'Test #1', 3, 5,
'Test #2', 5, 5,
'Test #3', 3, 15
]
| extend p_val=0.0
| invoke binomial_test_fl('x', 'n', 'p_val', success_prob=0.2, alt_hypotheis='greater')

Output

id x n p_val
Test #1 3 5 0.05792
Test #2 5 5 0.00032
Test #3 3 15 0.601976790745087
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