如何从冻结的Spicer.stats分布中获取参数自变量? [英] How to get parameter arguments from a frozen spicy.stats distribution?

问题描述

在 scipy.stats 中您可以创建 冻结分布，从而可以为该实例永久设置分布的参数化(形状，位置和比例).

In scipy.stats you can create a frozen distribution that allows the parameterization (shape, location & scale) of the distribution to be permanently set for that instance.

例如，您可以创建伽玛分布(

For example, you can create an gamma distribution (scipy.stats.gamma) with a,loc and scale parameters and freeze them so they do not have to be passed around every time that distribution is needed.

import scipy.stats as stats

# Parameters for this particular gamma distribution
a, loc, scale = 3.14, 5.0, 2.0

# Do something with the general distribution parameterized
print 'gamma stats:', stats.gamma(a, loc=loc, scale=scale).stats()

# Create frozen distribution
rv = stats.gamma(a, loc=loc, scale=scale)

# Do something with the specific, already parameterized, distribution
print 'rv stats   :', rv.stats()

---

gamma stats: (array(11.280000000000001), array(12.56))
rv stats   : (array(11.280000000000001), array(12.56))

可访问的rv参数?

由于此功能很可能不会传递参数，因此是否有办法在以后仅从冻结的分布rv中取回这些值?

Accessible rv parameters?

Since the parameters will most likely not be passed around as a result of this feature, is there a way to get those values back from only the frozen distribution, rv, later on?

推荐答案

访问rv冻结参数

是的，在分发实例中可以使用用于创建冻结分发的参数.它们存储在 args & kwds属性.这取决于发行版的实例是使用位置参数还是关键字参数创建的.

Accessing rv frozen parameters

Yes, the parameters used to create a frozen distribution are available within the instance of the distribution. They are stored within the args & kwds attribute. This will be dependent on if the distribution's instance was created with positional arguments or keyword arguments.

import scipy.stats as stats

# Parameters for this particular alpha distribution
a, loc, scale = 3.14, 5.0, 2.0

# Create frozen distribution
rv1 = stats.gamma(a, loc, scale)
rv2 = stats.gamma(a, loc=loc, scale=scale)

# Do something with frozen parameters
print 'positional and keyword'
print 'frozen args : {}'.format(rv1.args)
print 'frozen kwds : {}'.format(rv1.kwds)
print
print 'positional only'
print 'frozen args : {}'.format(rv2.args)
print 'frozen kwds : {}'.format(rv2.kwds)

---

positional and keyword
frozen args : (3.14, 5.0, 2.0)
frozen kwds : {}

positional only
frozen args : (3.14,)
frozen kwds : {'loc': 5.0, 'scale': 2.0}

奖金:处理args和kwds

的私有方法

有一个私有方法， .dist._parse_args() ，可以处理两种情况下的参数传递，并会返回一致的结果.

Bonus: Private method that handles both args and kwds

There is an private method, .dist._parse_args(), which handles both cases of parameter passing and will return a consistent result.

# Get the original parameters regardless of argument type
shape1, loc1, scale1 = rv1.dist._parse_args(*rv1.args, **rv1.kwds)
shape2, loc2, scale2 = rv2.dist._parse_args(*rv2.args, **rv2.kwds)

print 'positional and keyword'
print 'frozen parameters: shape={}, loc={}, scale={}'.format(shape1, loc1, scale1)
print
print 'positional only'
print 'frozen parameters: shape={}, loc={}, scale={}'.format(shape2, loc2, scale2)

---

positional and keyword
frozen parameters: shape=(3.14,), loc=5.0, scale=2.0

positional only
frozen parameters: shape=(3.14,), loc=5.0, scale=2.0

注意事项

允许使用私有方法通常是不好的做法，因为技术上内部的API总是可以更改的，但是，有时它们提供了不错的功能， Python中没有真正私有的东西:) .

Caveat

Granted, using private methods is typically bad practice because technically internal APIs can always change, however, sometimes they provide nice features, would be easy to re-implement should things change and nothing is really private in Python :).

这篇关于如何从冻结的Spicer.stats分布中获取参数自变量?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！