MeteoInfo/MeteoInfoLab/pylib/mipylib/numeric/stats/distributions.py

# coding=utf-8
#-----------------------------------------------------
# Author: Yaqiang Wang
# Date: 2018-3-20
# Purpose: MeteoInfoLab stats.distributions module
# Note: Jython
#-----------------------------------------------------

from org.apache.commons.math3.distribution import NormalDistribution, BetaDistribution, CauchyDistribution, \
    ChiSquaredDistribution, ExponentialDistribution, FDistribution, GammaDistribution, GumbelDistribution, \
    LaplaceDistribution, LevyDistribution, LogisticDistribution, LogNormalDistribution, NakagamiDistribution, \
    ParetoDistribution, TDistribution, TriangularDistribution, UniformRealDistribution, WeibullDistribution

from _distn_infrastructure import rv_continuous

__all__ = [
    'norm','beta','cauchy','chi2','expon','f','gamma','gumbel','laplace','levy','logistic','lognorm',
    'nakagami','pareto','t','triang','uniform','weibull'
    ]

class norm_gen(rv_continuous):
    '''
    A normal continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a normal distribution object.
        '''
        loc, scale = self._parse_args(*args)        
        dist = NormalDistribution(loc, scale)
        return dist

norm = norm_gen()

class beta_gen(rv_continuous):
    '''
    A beta continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a normal distribution object.
        '''
        loc, scale = self._parse_args(*args)        
        dist = BetaDistribution(loc, scale)
        return dist

beta = beta_gen()

class cauchy_gen(rv_continuous):
    '''
    A cauchy continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a cauchy distribution object.
        '''
        loc, scale = self._parse_args(*args)        
        dist = CauchyDistribution(loc, scale)
        return dist

cauchy = cauchy_gen()

class chi2_gen(rv_continuous):
    '''
    A chi squared continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a chi squared distribution object.
        '''
        dof = self._parse_args(*args)[0]     
        dist = ChiSquaredDistribution(dof)
        return dist

chi2 = chi2_gen()

class expon_gen(rv_continuous):
    '''
    A exponential continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a exponential distribution object.
        '''
        mean = self._parse_args(*args)[0]      
        dist = ExponentialDistribution(mean)
        return dist

expon = expon_gen()

class f_gen(rv_continuous):
    '''
    A F continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a F distribution object.
        '''
        loc, scale = self._parse_args(*args)        
        dist = FDistribution(loc, scale)
        return dist

f = f_gen()

class gamma_gen(rv_continuous):
    '''
    A gamma continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a gamma distribution object.
        '''
        loc, scale = self._parse_args(*args)        
        dist = GammaDistribution(loc, scale)
        return dist

gamma = gamma_gen()

class gumbel_gen(rv_continuous):
    '''
    A gumbel continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a gumbel distribution object.
        '''
        loc, scale = self._parse_args(*args)        
        dist = GumbelDistribution(loc, scale)
        return dist

gumbel = gumbel_gen()

class laplace_gen(rv_continuous):
    '''
    A Laplace continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a Laplace distribution object.
        '''
        loc, scale = self._parse_args(*args)        
        dist = LaplaceDistribution(loc, scale)
        return dist

laplace = laplace_gen()

class levy_gen(rv_continuous):
    '''
    A Levy continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a Levy distribution object.
        '''
        loc, scale = self._parse_args(*args)        
        dist = LevyDistribution(loc, scale)
        return dist

levy = levy_gen()

class logistic_gen(rv_continuous):
    '''
    A logistic continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a logistic distribution object.
        '''
        loc, scale = self._parse_args(*args)        
        dist = LogisticDistribution(loc, scale)
        return dist

logistic = logistic_gen()

class lognorm_gen(rv_continuous):
    '''
    A Log-normal continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a Log-normal distribution object.
        '''
        scale, shape = self._parse_args(*args)        
        dist = LogNormalDistribution(scale, shape)
        return dist

lognorm = lognorm_gen()

class nakagami_gen(rv_continuous):
    '''
    A Nakagami continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a Nakagami distribution object.
        '''
        scale, shape = self._parse_args(*args)        
        dist = NakagamiDistribution(scale, shape)
        return dist

nakagami = nakagami_gen()

class pareto_gen(rv_continuous):
    '''
    A Pareto continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a Pareto distribution object.
        '''
        scale, shape = self._parse_args(*args)        
        dist = ParetoDistribution(scale, shape)
        return dist

pareto = pareto_gen()

class t_gen(rv_continuous):
    '''
    A Student's t continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a Student's t-distribution object.
        '''
        dof = self._parse_args(*args)[0]     
        dist = TDistribution(dof)
        return dist

t = t_gen()

class triang_gen(rv_continuous):
    '''
    A Triangular continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a Triangular distribution object.
        '''
        r = self._parse_args(*args)
        if len(r) == 1:
            c = r[0]
            a = 0
            b = c
        else:
            a = r[0]
            c = r[2]
            b = a + r[1] * c
        dist = TriangularDistribution(a, c, b)
        return dist

triang = triang_gen()

class uniform_gen(rv_continuous):
    '''
    A Uniform continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a Uniform distribution object.
        '''
        scale, shape = self._parse_args(*args)        
        dist = UniformRealDistribution(scale, shape)
        return dist

uniform = uniform_gen()

class weibull_gen(rv_continuous):
    '''
    A Weibull continuous random variable.
    '''
    
    def _create_distribution(self, *args):
        '''
        Create a Weibull distribution object.
        '''
        scale, shape = self._parse_args(*args)        
        dist = WeibullDistribution(scale, shape)
        return dist

weibull = weibull_gen()