點估計的相對誤差

Python 中的抽樣

James Chapman

Curriculum Manager, DataCamp

樣本大小是列數

len(coffee_ratings.sample(n=300))

len(coffee_ratings.sample(frac=0.25))

coffee_ratings['total_cup_points'].mean()

82.15120328849028

coffee_ratings.sample(n=10)['total_cup_points'].mean()

83.027

coffee_ratings.sample(n=100)['total_cup_points'].mean()

82.4897

coffee_ratings.sample(n=1000)['total_cup_points'].mean()

82.1186

母體參數：

population_mean = coffee_ratings['total_cup_points'].mean()

點估計：

sample_mean = coffee_ratings.sample(n=sample_size)['total_cup_points'].mean()

相對誤差（百分比）：

rel_error_pct = 100 * abs(population_mean-sample_mean) / population_mean

import matplotlib.pyplot as plt
errors.plot(x="sample_size", 
            y="relative_error", 
            kind="line")
plt.show()

特性：

相對誤差與樣本大小的折線圖。

Python 中的抽樣