def two_sample_t_test(**kwargs):
variable_1 = kwargs['variable_1'].values
variable_2 = kwargs['variable_2'].values
sample_size_1 = variable_1.__len__()
sample_size_2 = variable_2.__len__()
shapiro_result_1 = shapiro.shapiro_wilk_test(variable_1)
shapiro_result_2 = shapiro.shapiro_wilk_test(variable_2)
t_value, p_value = stats.ttest_ind(variable_1, variable_2)
if not shapiro_result_1['accept_null'] and shapiro_result_2['accept_null']:
return {'t_value': None, 'p_value': None, 'sample_size_1': sample_size_1, 'sample_size_2': sample_size_2, 'interpretation': None,
'accept_null': False, 'shapiro_result_1':shapiro_result_1, 'shapiro_result_2': shapiro_result_2}
if sample_size_1 > 15 and sample_size_2 > 15:
if p_value <= 0.05:
interpretation = 'The means of the two variables are significantly different from each other (confidence interval 95%).'
accept_null = False
else:
interpretation = 'The means of the two variables are not significantly different from each other (confidence interval 95%).'
accept_null = True
else:
interpretation = 'The sample sizes are too small to conduct the test with statistical significance.'
accept_null = False
return {'t_value': t_value, 'p_value': p_value, 'sample_size_1': sample_size_1, 'sample_size_2': sample_size_2, 'accept_null': accept_null,
'interpretation': interpretation, 'shapiro_result_1': shapiro_result_1, 'shapiro_result_2': shapiro_result_2}
def one_sample_t_test(**kwargs):
variable = kwargs['variable'].values
sample_size = variable.__len__()
mean = kwargs['mean']
t_value, p_value = stats.ttest_1samp(variable, mean)
shapiro_result = shapiro.shapiro_wilk_test(variable)
if not shapiro_result['accept_null']:
return {'t_value': None, 'p_value': None, 'sample_size': sample_size, 'interpretation':None,
'accept_null': False, 'shapiro_result': shapiro_result}
if sample_size > 15:
if p_value <= 0.05:
interpretation = 'The mean of the variable is statistically significantly different from ' + str(mean) + ' (confidence interval 95%).'
accept_null = False
else:
interpretation = 'The mean of the variable is not significantly different from ' + str(mean) + ' (confidence interval 95%).'
accept_null = True
else:
interpretation = 'The sample size is too small to conduct the test with statistical significance.'
accept_null = False
return {'t_value': t_value, 'p_value': p_value, 'sample_size': sample_size, 'accept_null': accept_null, 'interpretation': interpretation,
'shapiro_result': shapiro_result}