pandas - Python: Implement mean of means 95% Confidence Interval? -
how can this solution implemented using pandas/python? question concerns implementation of finding 95% ci around mean of means using stats.stackexchange solution.
import pandas pd ipython.display import display import scipy import scipy.stats st import scikits.bootstrap bootstraps data = pd.dataframe({ "exp1":[34, 41, 39] ,"exp2":[45, 51, 52] ,"exp3":[29, 31, 35] }).t data.loc[:,"row_mean"] = data.mean(axis=1) data.loc[:,"row_std"] = data.std(axis=1) display(data)
<table border="1" class="dataframe"> <thead> <tr style="text-align: right;"> <th></th> <th>0</th> <th>1</th> <th>2</th> <th>row_mean</th> <th>row_std</th> </tr> </thead> <tbody> <tr> <th>exp1</th> <td>34</td> <td>41</td> <td>39</td> <td>38.000000</td> <td>2.943920</td> </tr> <tr> <th>exp2</th> <td>45</td> <td>51</td> <td>52</td> <td>49.333333</td> <td>3.091206</td> </tr> <tr> <th>exp3</th> <td>29</td> <td>31</td> <td>35</td> <td>31.666667</td> <td>2.494438</td> </tr> </tbody> </table>
mean_of_means = data.row_mean.mean() std_of_means = data.row_mean.std() confidence = 0.95 print("mean(means): {}\nstd(means):{}".format(mean_of_means,std_of_means))
- mean(means): 39.66666666666667
- std(means): 8.950481054731702
1st incorrect attempt (zscore):
zscore = st.norm.ppf(1-(1-confidence)/2) lower_bound = mean_of_means - (zscore*std_of_means) upper_bound = mean_of_means + (zscore*std_of_means) print("95% ci = [{},{}]".format(lower_bound,upper_bound))
- 95% ci = [22.1,57.2] (incorrect solution)
2nd incorrect attempt (tscore):
tscore = st.t.ppf(1-0.05, data.shape[0]) lower_bound = mean_of_means - (tscore*std_of_means) upper_bound = mean_of_means + (tscore*std_of_means) print("95% ci = [{},{}]".format(lower_bound,upper_bound))
- 95% ci = [18.60,60.73] (incorrect solution)
3rd incorrect attempt (boostrap):
cis = bootstraps.ci(data=data.row_mean, statfunction=scipy.mean,alpha=0.05)
- 95% ci = [31.67, 49.33] (incorrect solution)
how can this solution implemented using pandas/python correct solution below?
- 95% ci = [17.4 61.9] (correct solution)
thank jon bates.
import pandas pd import scipy import scipy.stats st data = pd.dataframe({ "exp1":[34, 41, 39] ,"exp2":[45, 51, 52] ,"exp3":[29, 31, 35] }).t data.loc[:,"row_mean"] = data.mean(axis=1) data.loc[:,"row_std"] = data.std(axis=1) tscore = st.t.ppf(1-0.025, data.shape[0]-1) print("mean(means): {}\nstd(means): {}\ntscore: {}".format(mean_of_means,std_of_means,tscore)) lower_bound = mean_of_means - (tscore*std_of_means/(data.shape[0]**0.5)) upper_bound = mean_of_means + (tscore*std_of_means/(data.shape[0]**0.5)) print("95% ci = [{},{}]".format(lower_bound,upper_bound))
mean(means): 39.66666666666667
std(means): 8.950481054731702
tscore: 4.302652729911275
95% ci = [17.432439139464606,61.90089419386874]
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