With the help of sympy.stats.MultivariateEwens() method, we can create a discrete random variable with Multivariate Ewens Distribution.
Syntax: sympy.stats.MultivariateEwens(syms, n, theta) Parameters: syms: the symbol n: size of the sample or the integer whose partitions are considered, a positive integer theta: mutation rate, must be positive real number Returns: a discrete random variable with Multivariate Ewens Distribution.
Example #1 :
Python3
# import sympy, MultivariateEwens, density, Symbol from sympy.stats.joint_rv_types import MultivariateEwens from sympy.stats import density from sympy import Symbol, pprint a = Symbol( 'a' , positive = True ) b = Symbol( 'b' , positive = True ) # using sympy.stats.MultivariateEwens() method E = MultivariateEwens( 'E' , 2 , 1 ) mveDist = density(E)(a, b) pprint(mveDist) |
Output :
/ -a2 | 2 |------- for a1 + 2*a2 = 2 <a1!*a2! | | 0 otherwise \
Example #2 :
Python3
# import sympy, MultivariateEwens, density, Symbol from sympy.stats.joint_rv_types import MultivariateEwens from sympy.stats import density from sympy import Symbol, pprint a = Symbol( 'a' , positive = True ) b = Symbol( 'b' , positive = True ) # using sympy.stats.MultivariateEwens() method E = MultivariateEwens( 'E' , 2 , 1 / 2 ) mveDist = density(E)(a, b) pprint(mveDist) |
Output :
/ -a1 -2*a2 |8*2 *2 |------------- for a1 + 2*a2 = 2 < 3*a1!*a2! | | 0 otherwise \