"""
Tests for the stats.mstats module (support for maskd arrays)
"""


import numpy as np
from numpy import nan
import numpy.ma as ma
from numpy.ma import masked, nomask

import scipy.stats.mstats as mstats
from numpy.testing import *
from numpy.ma.testutils import assert_equal, assert_almost_equal, \
    assert_array_almost_equal


class TestGMean(TestCase):
    def test_1D(self):
        a = (1,2,3,4)
        actual= mstats.gmean(a)
        desired = np.power(1*2*3*4,1./4.)
        assert_almost_equal(actual, desired,decimal=14)

        desired1 = mstats.gmean(a,axis=-1)
        assert_almost_equal(actual, desired1, decimal=14)
        assert not isinstance(desired1, ma.MaskedArray)
        #
        a = ma.array((1,2,3,4),mask=(0,0,0,1))
        actual= mstats.gmean(a)
        desired = np.power(1*2*3,1./3.)
        assert_almost_equal(actual, desired,decimal=14)

        desired1 = mstats.gmean(a,axis=-1)
        assert_almost_equal(actual, desired1, decimal=14)
    #
    def test_2D(self):
        a = ma.array(((1,2,3,4),(1,2,3,4),(1,2,3,4)),
                     mask=((0,0,0,0),(1,0,0,1),(0,1,1,0)))
        actual= mstats.gmean(a)
        desired = np.array((1,2,3,4))
        assert_array_almost_equal(actual, desired, decimal=14)
        #
        desired1 = mstats.gmean(a,axis=0)
        assert_array_almost_equal(actual, desired1, decimal=14)
        #
        actual= mstats.gmean(a, -1)
        desired = ma.array((np.power(1*2*3*4,1./4.),
                            np.power(2*3,1./2.),
                            np.power(1*4,1./2.)))
        assert_array_almost_equal(actual, desired, decimal=14)

class TestHMean(TestCase):
    def test_1D(self):
        a = (1,2,3,4)
        actual= mstats.hmean(a)
        desired =  4. / (1./1 + 1./2 + 1./3 + 1./4)
        assert_almost_equal(actual, desired, decimal=14)
        desired1 = mstats.hmean(ma.array(a),axis=-1)
        assert_almost_equal(actual, desired1, decimal=14)
        #
        a = ma.array((1,2,3,4),mask=(0,0,0,1))
        actual= mstats.hmean(a)
        desired = 3. / (1./1 + 1./2 + 1./3)
        assert_almost_equal(actual, desired,decimal=14)
        desired1 = mstats.hmean(a,axis=-1)
        assert_almost_equal(actual, desired1, decimal=14)

    def test_2D(self):
        a = ma.array(((1,2,3,4),(1,2,3,4),(1,2,3,4)),
                     mask=((0,0,0,0),(1,0,0,1),(0,1,1,0)))
        actual= mstats.hmean(a)
        desired = ma.array((1,2,3,4))
        assert_array_almost_equal(actual, desired, decimal=14)
        #
        actual1 = mstats.hmean(a,axis=-1)
        desired = (4./(1/1.+1/2.+1/3.+1/4.),
                   2./(1/2.+1/3.),
                   2./(1/1.+1/4.)
                   )
        assert_array_almost_equal(actual1, desired, decimal=14)


class TestRanking(TestCase):
    #
    def __init__(self, *args, **kwargs):
        TestCase.__init__(self, *args, **kwargs)
    #
    def test_ranking(self):
        x = ma.array([0,1,1,1,2,3,4,5,5,6,])
        assert_almost_equal(mstats.rankdata(x),[1,3,3,3,5,6,7,8.5,8.5,10])
        x[[3,4]] = masked
        assert_almost_equal(mstats.rankdata(x),[1,2.5,2.5,0,0,4,5,6.5,6.5,8])
        assert_almost_equal(mstats.rankdata(x,use_missing=True),
                            [1,2.5,2.5,4.5,4.5,4,5,6.5,6.5,8])
        x = ma.array([0,1,5,1,2,4,3,5,1,6,])
        assert_almost_equal(mstats.rankdata(x),[1,3,8.5,3,5,7,6,8.5,3,10])
        x = ma.array([[0,1,1,1,2], [3,4,5,5,6,]])
        assert_almost_equal(mstats.rankdata(x),[[1,3,3,3,5],[6,7,8.5,8.5,10]])
        assert_almost_equal(mstats.rankdata(x,axis=1),[[1,3,3,3,5],[1,2,3.5,3.5,5]])
        assert_almost_equal(mstats.rankdata(x,axis=0),[[1,1,1,1,1],[2,2,2,2,2,]])


class TestCorr(TestCase):
    #
    def test_pearsonr(self):
        "Tests some computations of Pearson's r"
        x = ma.arange(10)
        assert_almost_equal(mstats.pearsonr(x,x)[0], 1.0)
        assert_almost_equal(mstats.pearsonr(x,x[::-1])[0], -1.0)
        #
        x = ma.array(x, mask=True)
        pr = mstats.pearsonr(x,x)
        assert(pr[0] is masked)
        assert(pr[1] is masked)
    #
    def test_spearmanr(self):
        "Tests some computations of Spearman's rho"
        (x, y) = ([5.05,6.75,3.21,2.66],[1.65,2.64,2.64,6.95])
        assert_almost_equal(mstats.spearmanr(x,y)[0], -0.6324555)
        (x, y) = ([5.05,6.75,3.21,2.66,np.nan],[1.65,2.64,2.64,6.95,np.nan])
        (x, y) = (ma.fix_invalid(x), ma.fix_invalid(y))
        assert_almost_equal(mstats.spearmanr(x,y)[0], -0.6324555)
        #
        x = [ 2.0, 47.4, 42.0, 10.8, 60.1,  1.7, 64.0, 63.1,
              1.0,  1.4,  7.9,  0.3,  3.9,  0.3,  6.7]
        y = [22.6, 08.3, 44.4, 11.9, 24.6,  0.6,  5.7, 41.6,
              0.0,  0.6,  6.7,  3.8,  1.0,  1.2,  1.4]
        assert_almost_equal(mstats.spearmanr(x,y)[0], 0.6887299)
        x = [ 2.0, 47.4, 42.0, 10.8, 60.1,  1.7, 64.0, 63.1,
              1.0,  1.4,  7.9,  0.3,  3.9,  0.3,  6.7, np.nan]
        y = [22.6, 08.3, 44.4, 11.9, 24.6,  0.6,  5.7, 41.6,
              0.0,  0.6,  6.7,  3.8,  1.0,  1.2,  1.4, np.nan]
        (x, y) = (ma.fix_invalid(x), ma.fix_invalid(y))
        assert_almost_equal(mstats.spearmanr(x,y)[0], 0.6887299)
    #
    def test_kendalltau(self):
        "Tests some computations of Kendall's tau"
        x = ma.fix_invalid([5.05, 6.75, 3.21, 2.66,np.nan])
        y = ma.fix_invalid([1.65, 26.5, -5.93, 7.96, np.nan])
        z = ma.fix_invalid([1.65, 2.64, 2.64, 6.95, np.nan])
        assert_almost_equal(np.asarray(mstats.kendalltau(x,y)),
                            [+0.3333333,0.4969059])
        assert_almost_equal(np.asarray(mstats.kendalltau(x,z)),
                            [-0.5477226,0.2785987])
        #
        x = ma.fix_invalid([ 0, 0, 0, 0,20,20, 0,60, 0,20,
                            10,10, 0,40, 0,20, 0, 0, 0, 0, 0, np.nan])
        y = ma.fix_invalid([ 0,80,80,80,10,33,60, 0,67,27,
                            25,80,80,80,80,80,80, 0,10,45, np.nan, 0])
        result = mstats.kendalltau(x,y)
        assert_almost_equal(np.asarray(result), [-0.1585188, 0.4128009])
    #
    def test_kendalltau_seasonal(self):
        "Tests the seasonal Kendall tau."
        x = [[nan,nan,  4,  2, 16, 26,  5,  1,  5,  1,  2,  3,  1],
             [  4,  3,  5,  3,  2,  7,  3,  1,  1,  2,  3,  5,  3],
             [  3,  2,  5,  6, 18,  4,  9,  1,  1,nan,  1,  1,nan],
             [nan,  6, 11,  4, 17,nan,  6,  1,  1,  2,  5,  1,  1]]
        x = ma.fix_invalid(x).T
        output = mstats.kendalltau_seasonal(x)
        assert_almost_equal(output['global p-value (indep)'], 0.008, 3)
        assert_almost_equal(output['seasonal p-value'].round(2),
                            [0.18,0.53,0.20,0.04])
    #
    def test_pointbiserial(self):
        "Tests point biserial"
        x = [1,0,1,1,1,1,0,1,0,0,0,1,1,0,0,0,1,1,1,0,0,0,0,0,0,0,0,1,0,
             0,0,0,0,1,-1]
        y = [14.8,13.8,12.4,10.1,7.1,6.1,5.8,4.6,4.3,3.5,3.3,3.2,3.0,
             2.8,2.8,2.5,2.4,2.3,2.1,1.7,1.7,1.5,1.3,1.3,1.2,1.2,1.1,
             0.8,0.7,0.6,0.5,0.2,0.2,0.1,np.nan]
        assert_almost_equal(mstats.pointbiserialr(x, y)[0], 0.36149, 5)
    #
    def test_cov(self):
        "Tests the cov function."
        x = ma.array([[1,2,3],[4,5,6]], mask=[[1,0,0],[0,0,0]])
        c = mstats.cov(x[0])
        assert_equal(c, x[0].var(ddof=1))
        c = mstats.cov(x[1])
        assert_equal(c, x[1].var(ddof=1))
        c = mstats.cov(x)
        assert_equal(c[1,0], (x[0].anom()*x[1].anom()).sum())
        #
        x = [[nan,nan,  4,  2, 16, 26,  5,  1,  5,  1,  2,  3,  1],
             [  4,  3,  5,  3,  2,  7,  3,  1,  1,  2,  3,  5,  3],
             [  3,  2,  5,  6, 18,  4,  9,  1,  1,nan,  1,  1,nan],
             [nan,  6, 11,  4, 17,nan,  6,  1,  1,  2,  5,  1,  1]]
        x = ma.fix_invalid(x).T
        (winter,spring,summer,fall) = x.T
        #
        assert_almost_equal(mstats.cov(winter,winter,bias=True),
                            winter.var(ddof=0))
        assert_almost_equal(mstats.cov(winter,winter,bias=False),
                            winter.var(ddof=1))
        assert_almost_equal(mstats.cov(winter,spring)[0,1], 7.7)
        assert_almost_equal(mstats.cov(winter,spring)[1,0], 7.7)
        assert_almost_equal(mstats.cov(winter,summer)[0,1], 19.1111111, 7)
        assert_almost_equal(mstats.cov(winter,summer)[1,0], 19.1111111, 7)
        assert_almost_equal(mstats.cov(winter,fall)[0,1], 20)
        assert_almost_equal(mstats.cov(winter,fall)[1,0], 20)


class TestTrimming(TestCase):
    #
    def test_trim(self):
        "Tests trimming"
        a = ma.arange(10)
        assert_equal(mstats.trim(a), [0,1,2,3,4,5,6,7,8,9])
        a = ma.arange(10)
        assert_equal(mstats.trim(a,(2,8)), [None,None,2,3,4,5,6,7,8,None])
        a = ma.arange(10)
        assert_equal(mstats.trim(a,limits=(2,8),inclusive=(False,False)),
                     [None,None,None,3,4,5,6,7,None,None])
        a = ma.arange(10)
        assert_equal(mstats.trim(a,limits=(0.1,0.2),relative=True),
                     [None,1,2,3,4,5,6,7,None,None])
        #
        a = ma.arange(12)
        a[[0,-1]] = a[5] = masked
        assert_equal(mstats.trim(a,(2,8)),
                     [None,None,2,3,4,None,6,7,8,None,None,None])
        #
        x = ma.arange(100).reshape(10,10)
        trimx = mstats.trim(x,(0.1,0.2),relative=True,axis=None)
        assert_equal(trimx._mask.ravel(),[1]*10+[0]*70+[1]*20)
        trimx = mstats.trim(x,(0.1,0.2),relative=True,axis=0)
        assert_equal(trimx._mask.ravel(),[1]*10+[0]*70+[1]*20)
        trimx = mstats.trim(x,(0.1,0.2),relative=True,axis=-1)
        assert_equal(trimx._mask.T.ravel(),[1]*10+[0]*70+[1]*20)
        #
        x = ma.arange(110).reshape(11,10)
        x[1] = masked
        trimx = mstats.trim(x,(0.1,0.2),relative=True,axis=None)
        assert_equal(trimx._mask.ravel(),[1]*20+[0]*70+[1]*20)
        trimx = mstats.trim(x,(0.1,0.2),relative=True,axis=0)
        assert_equal(trimx._mask.ravel(),[1]*20+[0]*70+[1]*20)
        trimx = mstats.trim(x.T,(0.1,0.2),relative=True,axis=-1)
        assert_equal(trimx.T._mask.ravel(),[1]*20+[0]*70+[1]*20)
    #
    def test_trim_old(self):
        "Tests trimming."
        x = ma.arange(100)
        assert_equal(mstats.trimboth(x).count(), 60)
        assert_equal(mstats.trimtail(x,tail='r').count(), 80)
        x[50:70] = masked
        trimx = mstats.trimboth(x)
        assert_equal(trimx.count(), 48)
        assert_equal(trimx._mask, [1]*16 + [0]*34 + [1]*20 + [0]*14 + [1]*16)
        x._mask = nomask
        x.shape = (10,10)
        assert_equal(mstats.trimboth(x).count(), 60)
        assert_equal(mstats.trimtail(x).count(), 80)
    #
    def test_trimmedmean(self):
        "Tests the trimmed mean."
        data = ma.array([ 77, 87, 88,114,151,210,219,246,253,262,
                         296,299,306,376,428,515,666,1310,2611])
        assert_almost_equal(mstats.trimmed_mean(data,0.1), 343, 0)
        assert_almost_equal(mstats.trimmed_mean(data,(0.1,0.1)), 343, 0)
        assert_almost_equal(mstats.trimmed_mean(data,(0.2,0.2)), 283, 0)
    #
    def test_trimmed_stde(self):
        "Tests the trimmed mean standard error."
        data = ma.array([ 77, 87, 88,114,151,210,219,246,253,262,
                         296,299,306,376,428,515,666,1310,2611])
        assert_almost_equal(mstats.trimmed_stde(data,(0.2,0.2)), 56.13193, 5)
        assert_almost_equal(mstats.trimmed_stde(data,0.2), 56.13193, 5)
    #
    def test_winsorization(self):
        "Tests the Winsorization of the data."
        data = ma.array([ 77, 87, 88,114,151,210,219,246,253,262,
                         296,299,306,376,428,515,666,1310,2611])
        assert_almost_equal(mstats.winsorize(data,(0.2,0.2)).var(ddof=1),
                            21551.4, 1)
        data[5] = masked
        winsorized = mstats.winsorize(data)
        assert_equal(winsorized.mask, data.mask)


class TestMoments(TestCase):
    """
        Comparison numbers are found using R v.1.5.1
        note that length(testcase) = 4
        testmathworks comes from documentation for the
        Statistics Toolbox for Matlab and can be found at both
        http://www.mathworks.com/access/helpdesk/help/toolbox/stats/kurtosis.shtml
        http://www.mathworks.com/access/helpdesk/help/toolbox/stats/skewness.shtml
        Note that both test cases came from here.
    """
    testcase = [1,2,3,4]
    testmathworks = ma.fix_invalid([1.165 , 0.6268, 0.0751, 0.3516, -0.6965,
                                    np.nan])
    def test_moment(self):
        """
        mean((testcase-mean(testcase))**power,axis=0),axis=0))**power))"""
        y = mstats.moment(self.testcase,1)
        assert_almost_equal(y,0.0,10)
        y = mstats.moment(self.testcase,2)
        assert_almost_equal(y,1.25)
        y = mstats.moment(self.testcase,3)
        assert_almost_equal(y,0.0)
        y = mstats.moment(self.testcase,4)
        assert_almost_equal(y,2.5625)
    def test_variation(self):
        """variation = samplestd/mean """
##        y = stats.variation(self.shoes[0])
##        assert_almost_equal(y,21.8770668)
        y = mstats.variation(self.testcase)
        assert_almost_equal(y,0.44721359549996, 10)

    def test_skewness(self):
        """
            sum((testmathworks-mean(testmathworks,axis=0))**3,axis=0)/((sqrt(var(testmathworks)*4/5))**3)/5
        """
        y = mstats.skew(self.testmathworks)
        assert_almost_equal(y,-0.29322304336607,10)
        y = mstats.skew(self.testmathworks,bias=0)
        assert_almost_equal(y,-0.437111105023940,10)
        y = mstats.skew(self.testcase)
        assert_almost_equal(y,0.0,10)

    def test_kurtosis(self):
        """
            sum((testcase-mean(testcase,axis=0))**4,axis=0)/((sqrt(var(testcase)*3/4))**4)/4
            sum((test2-mean(testmathworks,axis=0))**4,axis=0)/((sqrt(var(testmathworks)*4/5))**4)/5
            Set flags for axis = 0 and
            fisher=0 (Pearson's definition of kurtosis for compatibility with Matlab)
        """
        y = mstats.kurtosis(self.testmathworks,0,fisher=0,bias=1)
        assert_almost_equal(y, 2.1658856802973,10)
        # Note that MATLAB has confusing docs for the following case
        #  kurtosis(x,0) gives an unbiased estimate of Pearson's skewness
        #  kurtosis(x)  gives a biased estimate of Fisher's skewness (Pearson-3)
        #  The MATLAB docs imply that both should give Fisher's
        y = mstats.kurtosis(self.testmathworks,fisher=0,bias=0)
        assert_almost_equal(y, 3.663542721189047,10)
        y = mstats.kurtosis(self.testcase,0,0)
        assert_almost_equal(y,1.64)
    #
    def test_mode(self):
        "Tests the mode"
        #
        a1 = [0,0,0,1,1,1,2,3,3,3,3,4,5,6,7]
        a2 = np.reshape(a1, (3,5))
        ma1 = ma.masked_where(ma.array(a1)>2,a1)
        ma2 = ma.masked_where(a2>2, a2)
        assert_equal(mstats.mode(a1, axis=None), (3,4))
        assert_equal(mstats.mode(ma1, axis=None), (0,3))
        assert_equal(mstats.mode(a2, axis=None), (3,4))
        assert_equal(mstats.mode(ma2, axis=None), (0,3))
        assert_equal(mstats.mode(a2, axis=0), ([[0,0,0,1,1]],[[1,1,1,1,1]]))
        assert_equal(mstats.mode(ma2, axis=0), ([[0,0,0,1,1]],[[1,1,1,1,1]]))
        assert_equal(mstats.mode(a2, axis=-1), ([[0],[3],[3]], [[3],[3],[1]]))
        assert_equal(mstats.mode(ma2, axis=-1), ([[0],[1],[0]], [[3],[1],[0]]))


class TestPercentile(TestCase):
    def setUp(self):
        self.a1 = [3,4,5,10,-3,-5,6]
        self.a2 = [3,-6,-2,8,7,4,2,1]
        self.a3 = [3.,4,5,10,-3,-5,-6,7.0]

    def test_percentile(self):
        x = np.arange(8) * 0.5
        assert_equal(mstats.scoreatpercentile(x, 0), 0.)
        assert_equal(mstats.scoreatpercentile(x, 100), 3.5)
        assert_equal(mstats.scoreatpercentile(x, 50), 1.75)

    def test_2D(self):
        x = ma.array([[1, 1, 1],
                      [1, 1, 1],
                      [4, 4, 3],
                      [1, 1, 1],
                      [1, 1, 1]])
        assert_equal(mstats.scoreatpercentile(x,50), [1,1,1])


class TestVariability(TestCase):
    """  Comparison numbers are found using R v.1.5.1
         note that length(testcase) = 4
    """
    testcase = ma.fix_invalid([1,2,3,4,np.nan])
    #
    def test_std(self):
        y = mstats.std(self.testcase)
        assert_almost_equal(y,1.290994449)

    def test_var(self):
        """
        var(testcase) = 1.666666667 """
        #y = stats.var(self.shoes[0])
        #assert_approx_equal(y,6.009)
        y = mstats.var(self.testcase)
        assert_almost_equal(y,1.666666667)

    def test_samplevar(self):
        """
        R does not have 'samplevar' so the following was used
        var(testcase)*(4-1)/4  where 4 = length(testcase)
        """
        #y = stats.samplevar(self.shoes[0])
        #assert_approx_equal(y,5.4081)
        y = mstats.samplevar(self.testcase)
        assert_almost_equal(y,1.25)

    def test_samplestd(self):
        #y = stats.samplestd(self.shoes[0])
        #assert_approx_equal(y,2.325532197)
        y = mstats.samplestd(self.testcase)
        assert_almost_equal(y,1.118033989)

    def test_signaltonoise(self):
        """
        this is not in R, so used
        mean(testcase,axis=0)/(sqrt(var(testcase)*3/4)) """
        #y = stats.signaltonoise(self.shoes[0])
        #assert_approx_equal(y,4.5709967)
        y = mstats.signaltonoise(self.testcase)
        assert_almost_equal(y,2.236067977)

    def test_stderr(self):
        """
        this is not in R, so used
        sqrt(var(testcase))/sqrt(4)
        """
##        y = stats.stderr(self.shoes[0])
##        assert_approx_equal(y,0.775177399)
        y = mstats.stderr(self.testcase)
        assert_almost_equal(y,0.6454972244)

    def test_sem(self):
        """
        this is not in R, so used
        sqrt(var(testcase)*3/4)/sqrt(3)
        """
        #y = stats.sem(self.shoes[0])
        #assert_approx_equal(y,0.775177399)
        y = mstats.sem(self.testcase)
        assert_almost_equal(y,0.6454972244)

    def test_z(self):
        """
        not in R, so used
        (10-mean(testcase,axis=0))/sqrt(var(testcase)*3/4)
        """
        y = mstats.z(self.testcase, ma.array(self.testcase).mean())
        assert_almost_equal(y,0.0)

    def test_zs(self):
        """
        not in R, so tested by using
        (testcase[i]-mean(testcase,axis=0))/sqrt(var(testcase)*3/4)
        """
        y = mstats.zs(self.testcase)
        desired = ma.fix_invalid([-1.3416407864999, -0.44721359549996 ,
                                  0.44721359549996 , 1.3416407864999, np.nan])
        assert_almost_equal(desired,y,decimal=12)



class TestMisc(TestCase):
    #
    def test_obrientransform(self):
        "Tests Obrien transform"
        args = [[5]*5+[6]*11+[7]*9+[8]*3+[9]*2+[10]*2,
                [6]+[7]*2+[8]*4+[9]*9+[10]*16]
        result = [5*[3.1828]+11*[0.5591]+9*[0.0344]+3*[1.6086]+2*[5.2817]+2*[11.0538],
                  [10.4352]+2*[4.8599]+4*[1.3836]+9*[0.0061]+16*[0.7277]]
        assert_almost_equal(np.round(mstats.obrientransform(*args).T,4),
                            result,4)
    #
    def test_kstwosamp(self):
        "Tests the Kolmogorov-Smirnov 2 samples test"
        x = [[nan,nan,  4,  2, 16, 26,  5,  1,  5,  1,  2,  3,  1],
             [  4,  3,  5,  3,  2,  7,  3,  1,  1,  2,  3,  5,  3],
             [  3,  2,  5,  6, 18,  4,  9,  1,  1,nan,  1,  1,nan],
             [nan,  6, 11,  4, 17,nan,  6,  1,  1,  2,  5,  1,  1]]
        x = ma.fix_invalid(x).T
        (winter,spring,summer,fall) = x.T
        #
        assert_almost_equal(np.round(mstats.ks_twosamp(winter,spring),4),
                            (0.1818,0.9892))
        assert_almost_equal(np.round(mstats.ks_twosamp(winter,spring,'g'),4),
                            (0.1469,0.7734))
        assert_almost_equal(np.round(mstats.ks_twosamp(winter,spring,'l'),4),
                            (0.1818,0.6744))
    #
    def test_friedmanchisq(self):
        "Tests the Friedman Chi-square test"
        # No missing values
        args = ([9.0,9.5,5.0,7.5,9.5,7.5,8.0,7.0,8.5,6.0],
                [7.0,6.5,7.0,7.5,5.0,8.0,6.0,6.5,7.0,7.0],
                [6.0,8.0,4.0,6.0,7.0,6.5,6.0,4.0,6.5,3.0])
        result = mstats.friedmanchisquare(*args)
        assert_almost_equal(result[0], 10.4737, 4)
        assert_almost_equal(result[1], 0.005317, 6)
        # Missing values
        x = [[nan,nan,  4,  2, 16, 26,  5,  1,  5,  1,  2,  3,  1],
             [  4,  3,  5,  3,  2,  7,  3,  1,  1,  2,  3,  5,  3],
             [  3,  2,  5,  6, 18,  4,  9,  1,  1,nan,  1,  1,nan],
             [nan,  6, 11,  4, 17,nan,  6,  1,  1,  2,  5,  1,  1]]
        x = ma.fix_invalid(x)
        result = mstats.friedmanchisquare(*x)
        assert_almost_equal(result[0], 2.0156, 4)
        assert_almost_equal(result[1], 0.5692, 4)


if __name__ == "__main__":
    run_module_suite()