The Journey Begins

I have started on a journey to know more about data science. There is a lot of science and statistics behind using big data tools and this blog is about making a few notes along the way.

One of the things I learnt today was about T-test. There is the Student's t-test and the Welch t-test. They are hypothesis tests on two samples. The t-test can be used, for example, to determine if two sets of data are significantly different from each other.

Below is a piece of code using the scipy library of python on using the Welch t-test.

import numpy
import scipy.stats
import pandas
def compare_averages(filename):
baseball_data = pandas.read_csv(filename)
l_data = baseball_data[baseball_data['handedness'] == 'L'] # select rows for left handed bastmen
r_data = baseball_data[baseball_data['handedness'] == 'R']
l_avg = l_data[['avg']] # select column for average
r_avg = r_data[['avg']]
test_statistic, p_value = scipy.stats.ttest_ind(l_avg, r_avg, equal_var=False)
test_statistic = test_statistic[0]
p_value = p_value[0]
hypothesis = True
if p_value < 0.05:
hypothesis = False
return (hypothesis, (test_statistic, p_value))
view raw dd01.py hosted with ❤ by GitHub

The baseball data is from the Lahman database.

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