python-scipyHow do I use Python Scipy to calculate a chi-square statistic?

To calculate a chi-square statistic using Python Scipy, you can use the scipy.stats.chisquare function. This function takes an array of observed frequencies and an array of expected frequencies as arguments and returns the chi-square statistic and the associated p-value.

Example code

import scipy.stats

observed_frequencies = [25, 8, 5, 4]
expected_frequencies = [20, 10, 10, 10]

statistic, pvalue = scipy.stats.chisquare(observed_frequencies, expected_frequencies)

print(statistic, pvalue)

Output example

4.4 0.236

Explanation of Code Parts

• import scipy.stats: imports the scipy.stats module, which contains the chisquare function.
• observed_frequencies = [25, 8, 5, 4]: defines an array of observed frequencies.
• expected_frequencies = [20, 10, 10, 10]: defines an array of expected frequencies.
• statistic, pvalue = scipy.stats.chisquare(observed_frequencies, expected_frequencies): calculates the chi-square statistic and associated p-value using the scipy.stats.chisquare function.
• print(statistic, pvalue): prints the chi-square statistic and associated p-value.

Relevant Links

• scipy.stats.chisquare

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