# Copyright (c) 2015, Ecole Polytechnique Federale de Lausanne, Blue Brain Project
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'''Test neurom.stats

Since the stats module consists of simple wrappers to scipy.stats functions,
these tests are only sanity checks.
'''

from neurom import stats as st
from nose import tools as nt
import numpy as np
import random

np.random.seed(42)

NORMAL_MU = 10.
NORMAL_SIGMA = 1.0
NORMAL = np.random.normal(NORMAL_MU, NORMAL_SIGMA, 1000)

EXPON_LAMBDA = 10.
EXPON = np.random.exponential(EXPON_LAMBDA, 1000)

UNIFORM_MIN = -1.
UNIFORM_MAX = 1.
UNIFORM = np.random.uniform(UNIFORM_MIN, UNIFORM_MAX, 1000)

def test_fit_normal_params():
    fit_ = st.fit(NORMAL, 'norm')
    nt.assert_almost_equal(fit_.params[0], NORMAL_MU, 1)
    nt.assert_almost_equal(fit_.params[1], NORMAL_SIGMA, 1)

def test_fit_normal_dict():
    fit_ = st.fit(NORMAL, 'norm')
    d = st.fit_results_to_dict(fit_, min_bound=-123, max_bound=123)
    nt.assert_almost_equal(d['mu'], NORMAL_MU, 1)
    nt.assert_almost_equal(d['sigma'], NORMAL_SIGMA, 1)
    nt.assert_almost_equal(d['min'], -123, 1)
    nt.assert_almost_equal(d['max'], 123, 1)

def test_fit_normal_regression():
    fit_ = st.fit(NORMAL, 'norm')
    nt.assert_almost_equal(fit_.params[0], 10.019332055822, 12)
    nt.assert_almost_equal(fit_.params[1], 0.978726207747, 12)
    nt.assert_almost_equal(fit_.errs[0], 0.021479979161, 12)
    nt.assert_almost_equal(fit_.errs[1], 0.745431659944, 12)


def test_fit_default_is_normal():
    fit0_ = st.fit(NORMAL)
    fit1_ = st.fit(NORMAL, 'norm')
    nt.eq_(fit0_.params, fit1_.params)
    nt.eq_(fit0_.errs, fit1_.errs)


def test_optimal_distribution_normal():
    optimal = st.optimal_distribution(NORMAL)
    nt.ok_(optimal.type == 'norm')


def test_optimal_distribution_exponential():
    optimal = st.optimal_distribution(EXPON)
    nt.ok_(optimal.type == 'expon')


def test_optimal_distribution_uniform():
    optimal = st.optimal_distribution(UNIFORM)
    nt.ok_(optimal.type == 'uniform')


def test_fit_results_dict_uniform():
    a = st.FitResults(params=[1, 2], errs=[3,4], type='uniform')
    d = st.fit_results_to_dict(a)
    nt.assert_equal(d['min'], 1)
    nt.assert_equal(d['max'], 3)
    nt.assert_equal(d['type'], 'uniform')

def test_fit_results_dict_uniform_min_max():
    a = st.FitResults(params=[1, 2], errs=[3,4], type='uniform')
    d = st.fit_results_to_dict(a, min_bound=-100, max_bound=100)
    nt.assert_equal(d['min'], 1)
    nt.assert_equal(d['max'], 3)
    nt.assert_equal(d['type'], 'uniform')


def test_fit_results_dict_normal():
    a = st.FitResults(params=[1, 2], errs=[3,4], type='norm')
    d = st.fit_results_to_dict(a)
    nt.assert_equal(d['mu'], 1)
    nt.assert_equal(d['sigma'], 2)
    nt.assert_equal(d['type'], 'normal')


def test_fit_results_dict_normal_min_max():
    a = st.FitResults(params=[1, 2], errs=[3,4], type='norm')
    d = st.fit_results_to_dict(a, min_bound=-100, max_bound=100)
    nt.assert_equal(d['mu'], 1)
    nt.assert_equal(d['sigma'], 2)
    nt.assert_equal(d['min'], -100)
    nt.assert_equal(d['max'], 100)
    nt.assert_equal(d['type'], 'normal')


def test_fit_results_dict_exponential():
    a = st.FitResults(params=[2, 2], errs=[3,4], type='expon')
    d = st.fit_results_to_dict(a)
    nt.assert_equal(d['lambda'], 1./2)
    nt.assert_equal(d['type'], 'exponential')


def test_fit_results_dict_exponential_min_max():
    a = st.FitResults(params=[2, 2], errs=[3,4], type='expon')
    d = st.fit_results_to_dict(a, min_bound=-100, max_bound=100)
    nt.assert_equal(d['lambda'], 1./2)
    nt.assert_equal(d['min'], -100)
    nt.assert_equal(d['max'], 100)
    nt.assert_equal(d['type'], 'exponential')

def test_scalar_stats():

    data = np.array([1.,2.,3.,4.,5.])

    result = st.scalar_stats(data)

    RESULT = {'mean': 3.,
              'max': 5.,
              'min': 1.,
              'std': 1.4142135623730951}

    nt.assert_true(RESULT == result)

def test_compare_two():
    data = np.array([1., 1., 2., 2.])
    data_same = np.array([1.0, 1.0, 2.0, 2.0])
    data_close = np.array([1.02, 1.01, 2.001, 2.0003])
    data_far = np.array([200., 100., 201])

    results1 = st.compare_two(data, data_same, test=st.StatTests.ks)
    nt.assert_almost_equal(results1.dist, 0.0)
    nt.assert_almost_equal(results1.pvalue, 1.0)

    results2 = st.compare_two(data, data_close, test=st.StatTests.ks)
    nt.assert_almost_equal(results2.dist, 0.5)
    nt.assert_almost_equal(results2.pvalue, 0.5344157, places=5)

    results3 = st.compare_two(data, data_far, test=st.StatTests.ks)
    nt.assert_almost_equal(results3.dist, 1.0)
    nt.assert_almost_equal(results3.pvalue, 0.0205039, places=5)

distr1 = np.ones(100)
distr2 = 2*np.ones(100)

def test_compare_two_ks():

    results1 = st.compare_two(distr1, distr1, test=st.StatTests.ks)
    nt.assert_almost_equal(results1.dist, 0.0, places=5)
    nt.assert_almost_equal(results1.pvalue, 1.0, places=5)