如何从数据帧执行测试？

Question

我想对男女员工的小时工资平均值进行t检验

`df1 = df[["gender","hourly_wage"]] #creating a sub-dataframe with only the columns of gender and hourly wage
staff_wages=df1.groupby(['gender']).mean() #grouping the data frame by gender and assigning it to a new variable 'staff_wages'
staff_wages.head()`

事实是，我想我已经糊涂了一半。我想做一个t检验，所以我写了代码

`mean_val_salary_female = df1[staff_wages['gender'] == 'female'].mean()
mean_val_salary_female = df1[staff_wages['gender'] == 'male'].mean()

t_val, p_val = stats.ttest_ind(mean_val_salary_female, mean_val_salary_male)

# obtain a one-tail p-value
p_val /= 2

print(f"t-value: {t_val}, p-value: {p_val}")`

它只会返回错误

我有点疯狂尝试不同的东西

`#married_vs_dependents = df[['married', 'num_dependents', 'years_in_employment']]


#married_vs_dependents = df[['married', 'num_dependents', 'years_in_employment']]
#married_vs_dependents.head()

#my_data = df(married_vs_dependents)
#my_data.groupby('married').mean()

mean_gender = df.groupby("gender")["hourly_wage"].mean()
married_vs_dependents.head()

mean_gender.groupby('gender').mean()

mean_val_salary_female = df[staff_wages['gender'] == 'female'].mean()
mean_val_salary_female = df[staff_wages['gender'] == 'male'].mean()

#cat1 = mean_gender['male']==['cat1']
#cat2 = mean_gender['female']==['cat2']

ttest_ind(cat1['gender'], cat2['hourly_wage'])`

请问谁能指引我走正确的一步

Answer 1

您将每个组的平均值作为a和b参数传递-这就是产生错误的原因。相反，您应该传递数组，如documentation中所述

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df1 = df[["gender","hourly_wage"]]

m = df1.loc[df1["gender"].eq("male")]["hourly_wage"].to_numpy()
f = df1.loc[df1["gender"].eq("female")]["hourly_wage"].to_numpy()

stats.ttest_ind(m,f)