package Math::GSL::Statistics::Test;
use base q{Test::Class};
use Test::More tests => 28;
use Math::GSL::Test qw/:all/;
use Math::GSL::Sort qw/:all/;
use Math::GSL::Errno qw/:all/;
use Math::GSL::Statistics qw/:all/;
use strict;

BEGIN { gsl_set_error_handler_off() }

sub make_fixture : Test(setup) {
    my $self = shift;
    $self->{data} =   [
        17, 18, 16, 18, 12,
        20, 18, 20, 20, 22,
        20, 10, 8, 12, 16,
        16, 18, 20, 18, 21
    ];
    $self->{datab} = [
        19, 20, 22, 24, 10,
        25, 20, 22, 21, 23,
        20, 10, 12, 14, 12,
        20, 22, 24, 23, 17
    ];
}

sub teardown : Test(teardown) {
}

sub GSL_STATS_MEAN : Tests {
    ok_similar( gsl_stats_mean([2 .. 5], 1, 4), 3.5 );
}

sub GSL_STATS_VARIANCE : Tests {
    ok_similar( gsl_stats_variance([2 .. 5], 1, 4), 5/3);
}

sub GSL_STATS_SD : Tests {
    my $self = shift;
    ok_similar( gsl_stats_sd($self->{data}, 1, 20)  , 3.79750610685209);
}

sub GSL_STATS_ABSDEV : Tests {
    my $self = shift;
    my $x = gsl_stats_absdev($self->{data},1, 20);
    ok_similar($x, 2.9); 
}

sub GSL_STATS_SKEW : Tests {
    my $self = shift;
    my $x = gsl_stats_skew($self->{data}, 1, 20);
    ok_similar($x, -0.909355923168064);
}

sub GSL_STATS_KURTOSIS : Tests {
    my $self = shift;
    my $x = gsl_stats_kurtosis($self->{data}, 1, 20);
    ok_similar_relative($x, -0.233692524908094);
}

sub GSL_STATS_COVARIANCE : Tests {
    my $self = shift;
    my $x = gsl_stats_covariance($self->{data}, 1, $self->{datab}, 1, 20); 
    ok_similar_relative($x, 14.5263157894737);
}

sub GSL_STATS_CORRELATION : Tests {
    my $self = shift;
    my $x = gsl_stats_correlation($self->{data}, 1, $self->{datab}, 1, 20);
    ok_similar_relative($x, 0.793090350710101); 
}

sub GSL_STATS_PVARIANCE : Tests {
    my $self = shift;
    my $x = gsl_stats_pvariance($self->{data}, 1, 20, $self->{datab}, 1, 20); 
    ok_similar_relative($x, 18.8421052631579);
}

sub GSL_STATS_TTEST : Tests {
    my $self = shift;
    my $x = gsl_stats_ttest($self->{data}, 1, 20, $self->{datab}, 1, 20); 
    ok_similar_relative($x, -1.45701922702927);
}

sub GSL_STATS_MAX : Tests { 
    my $self = shift;
    my $x = gsl_stats_max($self->{data}, 1, 20); 
    ok_similar_relative($x, 22);
}

sub GSL_STATS_MIN : Tests {
    my $self = shift;
    my $x = gsl_stats_min($self->{data}, 1, 20); 
    ok_similar_relative($x, 8);
}

sub GSL_STATS_MINMAX : Tests {
    my $self = shift;
    my ($min, $max) = gsl_stats_minmax($self->{data}, 1, 20); 
    ok_similar_relative($max, 22);
    ok_similar_relative($min, 8);
}

sub GSL_STATS_MAX_INDEX : Tests {
    my $self = shift;
    my $x = gsl_stats_max_index($self->{data}, 1, 20); 
    ok_similar_relative($x, 9);
}

sub GSL_STATS_MIN_INDEX : Tests {
    my $self = shift;
    my $x = gsl_stats_min_index($self->{data}, 1, 20); 
    ok_similar_relative($x, 12);
}

sub GSL_STATS_MINMAX_INDEX : Tests {
    my $self = shift;
    my ($min, $max) = gsl_stats_minmax_index($self->{data}, 1, 20); 
    ok_similar_relative($min, 12);
    ok_similar_relative($max, 9);
}

sub GSL_STATS_MEDIAN_FROM_SORTED_DATA_EVEN : Tests {
    my $self = shift;
    my $sorted = gsl_sort($self->{data}, 1, 20);
    my $x = gsl_stats_median_from_sorted_data($sorted, 1, 20);
    ok_similar_relative($x, 18);
}

sub GSL_STATS_MEDIAN_FROM_SORTED_DATA_ODD : Tests {
    my $self = shift;
    my $sorted = gsl_sort($self->{data}, 1, 20);
    my $x = gsl_stats_median_from_sorted_data($sorted, 1, 19);
    ok_similar_relative($x, 18);
}

sub GSL_STATS_QUANTILE_FROM_SORTED_DATA_0 : Tests {
    my $self = shift;
    my $sorted = gsl_sort($self->{data}, 1, 20);
    my $x = gsl_stats_quantile_from_sorted_data($sorted, 1, 20, 0);
    ok_similar_relative($x, 8);
}

sub GSL_STATS_QUANTILE_FROM_SORTED_DATA_100 : Tests {
    my $self = shift;
    my $sorted = gsl_sort($self->{data}, 1, 20);
    my $x = gsl_stats_quantile_from_sorted_data($sorted, 1, 20, 1);
    ok_similar_relative($x, 22);
}

sub GSL_STATS_QUANTILE_FROM_SORTED_DATA_50_EVEN : Tests {
    my $self = shift;
    my $sorted = gsl_sort($self->{data}, 1, 20);
    my $x = gsl_stats_quantile_from_sorted_data($sorted, 1, 20, 0.5);
    ok_similar_relative($x, 18);
}

sub GSL_STATS_QUANTILE_FROM_SORTED_DATA_50_ODD : Tests {
    my $self = shift;
    my $sorted = gsl_sort($self->{data}, 1, 20);
    my $x = gsl_stats_quantile_from_sorted_data($sorted, 1, 20, 0.5);
    ok_similar_relative($x, 18);
}

sub GSL_STATS_LAG1_AUTOCORRELATION : Tests {
    my $nacc3 = 1001 ;
    my $i;
    my $numacc3;
    $numacc3->[0] = 1000000.2 ;
    for ($i = 1 ; $i < 1000  ; $i += 2) {
        $numacc3->[$i] = 1000000.1 ;
        $numacc3->[$i+1] = 1000000.3 ; 
    }
    my $mean = gsl_stats_mean ($numacc3, 1, $nacc3);
    my $sd = gsl_stats_sd ($numacc3, 1, $nacc3);
    my $lag1 = gsl_stats_lag1_autocorrelation ($numacc3, 1, $nacc3);

    my $expected_mean = 1000000.2;
    my $expected_sd = 0.1;
    my $expected_lag1 = -0.999;

    ok_similar_relative($mean, $expected_mean);
    ok_similar_relative($sd, $expected_sd);
    ok_similar_relative($lag1, $expected_lag1);
}

sub GSL_STATS_WMEAN : Tests {
    my $w = [4, 4, 2, 2];
    my $data = [2, 3, 4, 5];
    my $mean = gsl_stats_wmean($w, 1, $data, 1, 4);
    ok_similar ($mean, 19/6);    
}

Test::Class->runtests;