Esempio n. 1
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def _class_sizes():
    # start with the actual distribution of class sizes from the book
    d = {
        7: 8,
        12: 8,
        17: 14,
        22: 4,
        27: 6,
        32: 12,
        37: 8,
        42: 3,
        47: 2,
    }

    # form the pmf
    pmf = _04_Pmf._make_pmf_from_dict(d, 'actual')
    print('mean', pmf._mean())
    print('var', pmf._var())

    # compute the biased pmf
    biased_pmf = _bias_pmf(pmf, 'observed')
    print('mean', biased_pmf._mean())
    print('var', biased_pmf._var())

    # unbias the biased pmf
    unbiased_pmf = _unbias_pmf(biased_pmf, 'unbiased')
    print('mean', unbiased_pmf._mean())
    print('var', unbiased_pmf._var())

    # plot the Pmfs
    _05_myplot._pmfs([pmf, biased_pmf])
    _05_myplot._show(xlabel='Class size', ylabel='PMF')
Esempio n. 2
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def _plot_ages(resp):
    """Plot the distribution of ages."""
    ages = [r.age for r in resp.records]
    cdf = _13_Cdf._make_cdf_from_list(ages)
    _05_myplot._clf()
    _05_myplot._cdf(cdf)
    _05_myplot._show()
Esempio n. 3
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def main():
    results = _read_results()
    speeds = _get_speeds(results)
    pmf = _04_Pmf._make_pmf_from_list(speeds, 'speeds')
    _05_myplot._pmf(pmf)
    _05_myplot._show(title='PMF of running speed',
                     xlabel='speed (mph)',
                     ylabel='probability')
Esempio n. 4
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def _check_cdf2():
    """Compare chi2 values from the simulation with a chi-squared dist."""
    df = 3
    t = [_simulate_chi2() for i in range(1000)]
    t2 = [scipy.stats.chi2.cdf(x, df) for x in t]
    cdf = _13_Cdf._make_cdf_from_list(t2)

    _05_myplot._cdf(cdf)
    _05_myplot._show()
Esempio n. 5
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def main():
    suite = _make_uniform_suite(0.0, 1.0, 1001)
    evidence = 140, 110

    _update(suite, evidence)
    suite.name = 'posterior'

    # plot the posterior distributions
    _05_myplot._pmf(suite)
    _05_myplot._show(title='Biased coin',
                     xlabel='P(heads)',
                     ylabel='Posterior probability')