如果我理解正确的话,应该这样做。
from itertools import product
import numpy as np
# Generate fake data.
keys = np.arange(100, 130)
populations = {}
samples = {}
for k in keys:
loc = np.random.uniform(-9.0, +9.0)
scale = np.random.uniform(0.4, 4.0)
n = np.random.randint(400, 800)
m = np.random.randint(20, 100)
populations[k] = np.random.normal(loc, scale, n)
samples[k] = np.random.choice(populations[k], m, replace=False)
print('data: key={} pop={} samp={}'.format(k, len(populations[k]), len(samples[k])))
def ttest_(d, p, n=1000):
result = {}
percentiles = (np.arange(n) + 0.5) / n
for k, (pop, sample) in d.items():
size_sample = len(sample)
mean_sample = np.mean(sample)
sd_sample = np.std(sample, ddof=1)
# Generate a distribution of t values.
tvalues = np.zeros(n)
for i in range(n):
sample2 = np.random.choice(pop, size=size_sample, replace=True)
size_sample2 = len(sample2)
mean_sample2 = np.mean(sample2)
sd_sample2 = np.std(sample2, ddof=1)
# Welch's t-test for sample and sample2.
tvalues[i] = (mean_sample - mean_sample2) / \
np.sqrt((sd_sample / np.sqrt(size_sample))**2 +
(sd_sample2 / np.sqrt(size_sample2))**2)
# Interpolate the quantile function at p.
tvalues.sort()
result[k] = round(np.interp(p, percentiles, tvalues), 2)
return result
pairs = {}
for (k, v), (k2, v2) in product(populations.items(), samples.items()):
if k == k2:
pairs[k] = (v, v2)
result = ttest_(pairs, p=0.5)
for k, v in result.items():
print('result: key={} t={}'.format(k, v))