
    >hB                     b    S r SSKJr  SSKrSSKJr  SS jrS rSS jr	 SS jr
SS	 jrSS
 jrg)a  extra statistical function and helper functions

contains:

* goodness-of-fit tests
  - powerdiscrepancy
  - gof_chisquare_discrete
  - gof_binning_discrete



Author: Josef Perktold
License : BSD-3

changes
-------
2013-02-25 : add chisquare_power, effectsize and "value"

    )lrangeN)statsc                 
   [         R                  " U 5      n[         R                  " U5      n[        U[        5      (       d  UnO8US:X  a  SnO/US:X  a  SnO&US:X  a  SnOUS:X  a  SnOUS	:X  a  S
nO[	        S5      e[         R
                  " XSS9nUn	UR                  S:  a`  [         R                  " U5      nUS:X  a  UR                  n	UR                  S:X  a(  [         R                  " U5      nUS:X  a  UR                  n[         R                  " [         R
                  " XcS9USSS9(       a	  USU	-  -  n
O@[         R                  " [         R
                  " XcS9SSSS9(       a  Un
X-  nO[	        S5      eUR                  U   nUR                  U   U:w  a  [	        S5      eUS:X  a;  SU-  [         R
                  " USU	-  -  [         R                  " XV-  5      -  US9-  nOvUS:X  a;  SU-  [         R
                  " USU	-  -  [         R                  " Xe-  5      -  US9-  nO5SU-  U-  US-   -  [         R
                  " USU	-  -  XV-  U-  S-
  -  US9-  nU[        R                  R                  XS-
  U-
  5      4$ )a.  Calculates power discrepancy, a class of goodness-of-fit tests
as a measure of discrepancy between observed and expected data.

This contains several goodness-of-fit tests as special cases, see the
description of lambd, the exponent of the power discrepancy. The pvalue
is based on the asymptotic chi-square distribution of the test statistic.

freeman_tukey:
D(x|\theta) = \sum_j (\sqrt{x_j} - \sqrt{e_j})^2

Parameters
----------
o : Iterable
    Observed values
e : Iterable
    Expected values
lambd : {float, str}
    * float : exponent `a` for power discrepancy
    * 'loglikeratio': a = 0
    * 'freeman_tukey': a = -0.5
    * 'pearson': a = 1   (standard chisquare test statistic)
    * 'modified_loglikeratio': a = -1
    * 'cressie_read': a = 2/3
    * 'neyman' : a = -2 (Neyman-modified chisquare, reference from a book?)
axis : int
    axis for observations of one series
ddof : int
    degrees of freedom correction,

Returns
-------
D_obs : Discrepancy of observed values
pvalue : pvalue


References
----------
Cressie, Noel  and Timothy R. C. Read, Multinomial Goodness-of-Fit Tests,
    Journal of the Royal Statistical Society. Series B (Methodological),
    Vol. 46, No. 3 (1984), pp. 440-464

Campbell B. Read: Freeman-Tukey chi-squared goodness-of-fit statistics,
    Statistics & Probability Letters 18 (1993) 271-278

Nobuhiro Taneichi, Yuri Sekiya, Akio Suzukawa, Asymptotic Approximations
    for the Distributions of the Multinomial Goodness-of-Fit Statistics
    under Local Alternatives, Journal of Multivariate Analysis 81, 335?359 (2002)
Steele, M. 1,2, C. Hurst 3 and J. Chaseling, Simulated Power of Discrete
    Goodness-of-Fit Tests for Likert Type Data

Examples
--------

>>> observed = np.array([ 2.,  4.,  2.,  1.,  1.])
>>> expected = np.array([ 0.2,  0.2,  0.2,  0.2,  0.2])

for checking correct dimension with multiple series

>>> powerdiscrepancy(np.column_stack((observed,observed)).T, 10*expected, lambd='freeman_tukey',axis=1)
(array([[ 2.745166,  2.745166]]), array([[ 0.6013346,  0.6013346]]))
>>> powerdiscrepancy(np.column_stack((observed,observed)).T, 10*expected,axis=1)
(array([[ 2.77258872,  2.77258872]]), array([[ 0.59657359,  0.59657359]]))
>>> powerdiscrepancy(np.column_stack((observed,observed)).T, 10*expected, lambd=0,axis=1)
(array([[ 2.77258872,  2.77258872]]), array([[ 0.59657359,  0.59657359]]))
>>> powerdiscrepancy(np.column_stack((observed,observed)).T, 10*expected, lambd=1,axis=1)
(array([[ 3.,  3.]]), array([[ 0.5578254,  0.5578254]]))
>>> powerdiscrepancy(np.column_stack((observed,observed)).T, 10*expected, lambd=2/3.0,axis=1)
(array([[ 2.89714546,  2.89714546]]), array([[ 0.57518277,  0.57518277]]))
>>> powerdiscrepancy(np.column_stack((observed,observed)).T, expected, lambd=2/3.0,axis=1)
(array([[ 2.89714546,  2.89714546]]), array([[ 0.57518277,  0.57518277]]))
>>> powerdiscrepancy(np.column_stack((observed,observed)), expected, lambd=2/3.0, axis=0)
(array([[ 2.89714546,  2.89714546]]), array([[ 0.57518277,  0.57518277]]))

each random variable can have different total count/sum

>>> powerdiscrepancy(np.column_stack((observed,2*observed)), expected, lambd=2/3.0, axis=0)
(array([[ 2.89714546,  5.79429093]]), array([[ 0.57518277,  0.21504648]]))
>>> powerdiscrepancy(np.column_stack((observed,2*observed)), expected, lambd=2/3.0, axis=0)
(array([[ 2.89714546,  5.79429093]]), array([[ 0.57518277,  0.21504648]]))
>>> powerdiscrepancy(np.column_stack((2*observed,2*observed)), expected, lambd=2/3.0, axis=0)
(array([[ 5.79429093,  5.79429093]]), array([[ 0.21504648,  0.21504648]]))
>>> powerdiscrepancy(np.column_stack((2*observed,2*observed)), 20*expected, lambd=2/3.0, axis=0)
(array([[ 5.79429093,  5.79429093]]), array([[ 0.21504648,  0.21504648]]))
>>> powerdiscrepancy(np.column_stack((observed,2*observed)), np.column_stack((10*expected,20*expected)), lambd=2/3.0, axis=0)
(array([[ 2.89714546,  5.79429093]]), array([[ 0.57518277,  0.21504648]]))
>>> powerdiscrepancy(np.column_stack((observed,2*observed)), np.column_stack((10*expected,20*expected)), lambd=-1, axis=0)
(array([[ 2.77258872,  5.54517744]]), array([[ 0.59657359,  0.2357868 ]]))
loglikeratior   freeman_tukeyg      pearson   modified_loglikeratiocressie_readgUUUUUU?znlambd has to be a number or one of loglikeratio, freeman_tukey, pearson, modified_loglikeratio or cressie_read)axis:0yE>)rtolatol      ?zZobserved and expected need to have the same number of observations, or e needs to add to 1z:observed and expected need to have the same number of bins   )nparray
isinstancestr
ValueErrorsumsize
atleast_2dTndimallcloseshapelogr   chi2sf)observedexpectedlambdr   ddofoeanntpkD_obss                hC:\Users\julio\OneDrive\Documentos\Trabajo\Ideas Frescas\venv\Lib\site-packages\statsmodels/stats/gof.pypowerdiscrepancyr/      sP   r 	A
AeS!!N"Ao%AiA--An$A E F F 	qA	
BvvaxMM!19B66Q;a AqyCC	{{266!'A>s2vJ	RVVA)14a	@F J K 	K	Awwt} * + 	+ 	Av!bffQBZ"&&+5DAA	
b!bffQBZ"&&+5DAA!AqsbffQBZAC!8a<%@tLL%**--c$h///    c                    [        U5      nSnSU-  n[        [        U R                  S5      [	        U R
                  S5      S-   5      nSn	[        U R                  S5      /n
/ nU HT  nU R                  " U/UQ76 nX-
  US-
  :  d  M#  U
R                  U5        UR                  X-
  5        Un	USU-
  :  d  MT    O   U
S   U R
                  :  a/  U
R                  U R
                  5        UR                  SU	-
  5        [        R                  " U
5      n
[        R                  " U5      nU
S	-   nU R                  US'   [        R                  " X.5      u  nnU R                  " U
/UQ76 n[        R                  " [        R                  " U5      X[-  5      u  nnUUUU:  S
U< S[        U5      < S[        U5      < 34$ )a9  perform chisquare test for random sample of a discrete distribution

Parameters
----------
distname : str
    name of distribution function
arg : sequence
    parameters of distribution
alpha : float
    significance level, threshold for p-value

Returns
-------
result : bool
    0 if test passes, 1 if test fails

Notes
-----
originally written for scipy.stats test suite,
still needs to be checked for standalone usage, insufficient input checking
may not run yet (after copy/paste)

refactor: maybe a class, check returns, or separate binning from
    test results
   r     r	   r   +=r   r   zchisquare - test for z	at arg = z with pval = )lenr   maxr(   minbcdfappendr   r   	histogramr   	chisquarer   )distfnargrvsalphamsgr)   nsuppwsuppdistsupportlastdistsuppdistmassiicurrenthistsuppfreqhsuppcdfschispvals                       r.   gof_chisquare_discreterQ      s   : 	CAEIE VXXu-s688T/BQ/FGKDFHHe$%HH**R%%>U5[(OOBOOGN+D!E'"  |vxx!$xx!Hxx!H }H((HQK ,,s,KD%::h$$D//"((4.<KT$u+.s3xD	(C C Cr0   c                 
   [        U 5      nSU-  n[        [        UR                  S5      [	        UR
                  S5      S-   5      nSn[        UR                  S5      /n/ n	U HT  n
UR                  " U
/UQ76 nX-
  US-
  :  d  M#  UR                  U
5        U	R                  X-
  5        UnUSU-
  :  d  MT    O   US   UR
                  :  a/  UR                  UR
                  5        U	R                  SU-
  5        [        R                  " U5      n[        R                  " U	5      n	US-   nUR                  US'   [        R                  " X5      u  pUR                  " U/UQ76 n[        R                  " U5      XI-  U4$ )	ai  get bins for chisquare type gof tests for a discrete distribution

Parameters
----------
rvs : ndarray
    sample data
distname : str
    name of distribution function
arg : sequence
    parameters of distribution
nsupp : int
    number of bins. The algorithm tries to find bins with equal weights.
    depending on the distribution, the actual number of bins can be smaller.

Returns
-------
freq : ndarray
    empirical frequencies for sample; not normalized, adds up to sample size
expfreq : ndarray
    theoretical frequencies according to distribution
histsupp : ndarray
    bin boundaries for histogram, (added 1e-8 for numerical robustness)

Notes
-----
The results can be used for a chisquare test ::

    (chis,pval) = stats.chisquare(freq, expfreq)

originally written for scipy.stats test suite,
still needs to be checked for standalone usage, insufficient input checking
may not run yet (after copy/paste)

refactor: maybe a class, check returns, or separate binning from
    test results
todo :
  optimal number of bins ? (check easyfit),
  recommendation in literature at least 5 expected observations in each bin

r   r3   r4   r	   r   r5   r   r   )r6   r   r7   r(   r8   r9   r:   r;   r   r   r<   )r@   r>   r?   rC   r)   rD   rE   rF   rG   rH   rI   rJ   rK   rL   rM   rN   s                   r.   gof_binning_discreterS      sX   X 	CAIE VXXu-s688T/BQ/FGKDFHHe$%HH**R%%>U5[(OOBOOGN+D!E'"  |vxx!$xx!Hxx!H }H((HQK c+JD::h$$D88D>1:x//r0   c                    [         R                  " U 5      n [        U 5      nU R                  S5      nUc8  [         R                  " U[
        5      nUR                  U[        U5      -  5        [         R                  " U[
        5      nX-
  S-  U-  R                  S5      nUS:X  a&  [        R                  R                  XuS-
  U-
  5      nO,[        R                  R                  XuS-
  U-
  US-  U-  5      nU(       a  Xx4$ Xx4$ )a'  chisquare goodness-of-fit test

The null hypothesis is that the distance between the expected distribution
and the observed frequencies is ``value``. The alternative hypothesis is
that the distance is larger than ``value``. ``value`` is normalized in
terms of effect size.

The standard chisquare test has the null hypothesis that ``value=0``, that
is the distributions are the same.


Notes
-----
The case with value greater than zero is similar to an equivalence test,
that the exact null hypothesis is replaced by an approximate hypothesis.
However, TOST "reverses" null and alternative hypothesis, while here the
alternative hypothesis is that the distance (divergence) is larger than a
threshold.

References
----------
McLaren, ...
Drost,...

See Also
--------
powerdiscrepancy
scipy.stats.chisquare

r   r   r	   )r   asarrayr6   r   emptyfloatfillr   r    r!   ncx2)	f_obsf_expvaluer%   return_basicn_binsnobschisqpvalues	            r.   r=   r=   T  s    @ JJuEZF99Q<D}'

4%-'(JJue$Ema%',,Q/Ezuqj4&78uqj4&7DI}}r0   c                     [         R                  R                  X2S-
  U-
  5      n[         R                  R	                  XRS-
  U-
  U S-  U-  5      nU$ )a  power of chisquare goodness of fit test

effect size is sqrt of chisquare statistic divided by nobs

Parameters
----------
effect_size : float
    This is the deviation from the Null of the normalized chi_square
    statistic. This follows Cohen's definition (sqrt).
nobs : int or float
    number of observations
n_bins : int (or float)
    number of bins, or points in the discrete distribution
alpha : float in (0,1)
    significance level of the test, default alpha=0.05

Returns
-------
power : float
    power of the test at given significance level at effect size

Notes
-----
This function also works vectorized if all arguments broadcast.

This can also be used to calculate the power for power divergence test.
However, for the range of more extreme values of the power divergence
parameter, this power is not a very good approximation for samples of
small to medium size (Drost et al. 1989)

References
----------
Drost, ...

See Also
--------
chisquare_effectsize
statsmodels.stats.GofChisquarePower

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                  " U5      $ U$ )a  effect size for a chisquare goodness-of-fit test

Parameters
----------
probs0 : array_like
    probabilities or cell frequencies under the Null hypothesis
probs1 : array_like
    probabilities or cell frequencies under the Alternative hypothesis
    probs0 and probs1 need to have the same length in the ``axis`` dimension.
    and broadcast in the other dimensions
    Both probs0 and probs1 are normalized to add to one (in the ``axis``
    dimension).
correction : None or tuple
    If None, then the effect size is the chisquare statistic divide by
    the number of observations.
    If the correction is a tuple (nobs, df), then the effectsize is
    corrected to have less bias and a smaller variance. However, the
    correction can make the effectsize negative. In that case, the
    effectsize is set to zero.
    Pederson and Johnson (1990) as referenced in McLaren et all. (1994)
cohen : bool
    If True, then the square root is returned as in the definition of the
    effect size by Cohen (1977), If False, then the original effect size
    is returned.
axis : int
    If the probability arrays broadcast to more than 1 dimension, then
    this is the axis over which the sums are taken.

Returns
-------
effectsize : float
    effect size of chisquare test

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