Python 中的 sympy.stats .多项式()函数
借助方法，我们可以创建一个具有多项式分布的离散随机变量。
多项式分布是多项式实验结果的概率分布。
Syntax: sympy.stats.Multinomial(syms, n, p)
Parameters:
syms: the symbol
n: is the number of trials, a positive integer
p: event probabilites, p>= 0 and p<= 1
Returns: a discrete random variable with Multinomial Distribution
示例#1 :
蟒蛇 3
# import sympy, Multinomial, density, symbols
from sympy.stats.joint_rv_types import Multinomial
from sympy.stats import density
from sympy import symbols, pprint
x1, x2, x3 = symbols('x1, x2, x3', nonnegative = True, integer = True)
p1, p2, p3 = symbols('p1, p2, p3', positive = True)
# Using sympy.stats.Multinomial() method
M = Multinomial('M', 3, p1, p2, p3)
multiDist = density(M)(x1, x2, x3)
pprint(multiDist)
输出:
/ x1 x2 x3
|6*p1 *p2 *p3
|---------------- for x1 + x2 + x3 = 3
< x1!*x2!*x3!
|
| 0 otherwise
\
例 2 :
蟒蛇 3
# import sympy, Multinomial, density, symbols
from sympy.stats.joint_rv_types import Multinomial
from sympy.stats import density
from sympy import symbols, pprint
x1, x2, x3 = symbols('x1, x2, x3', nonnegative = True, integer = True)
# Using sympy.stats.Multinomial() method
M = Multinomial('M', 4, 0, 1, 0)
multiDist = density(M)(x1, x2, x3)
pprint(multiDist)
输出:
/ x1 x3
| 24*0 *0
|----------- for x1 + x2 + x3 = 4
<x1!*x2!*x3!
|
| 0 otherwise
\
