擅长:python、mysql、java
<p>好的,因为您刚刚构建了示例,并使用了wikipedia中的符号(第一节,mu和sigma)以及您给出的示例:</p>
<pre><code>from numpy import log, exp, sqrt
import numpy as np
mu = -10
scale = sqrt(2*10) # scale is sigma, not variance
tmp1 = np.random.normal(loc=mu, scale=scale, size=1e8)
# Just checking
print tmp1.mean(), tmp1.std()
# 10.0011028634 4.47048010775, perfectly accurate
tmp1_exp = exp(tmp1) # Not sensible to use the same name for two samples
# WIKIPEDIA NOTATION!
m = tmp1_exp.mean() # until proven wrong, this is a meassure of the mean
v = tmp1_exp.var() # again, until proven wrong, this is sigma**2
#Now, according to wikipedia
print "This: ", log(m**2/sqrt(v+m**2)), "should be similar to", mu
# I get This: 13.9983309499 should be similar to 10
print "And this:", sqrt(log(1+v/m**2)), "should be similar to", scale
# I get And this: 3.39421327037 should be similar to 4.472135955
</code></pre>
<p>所以,即使这些值并不完全完美,我也不认为它们是完全错误的。在</p>