import numpy as npimport matplotlib.pyplot as pltfrom scipy import statsdef plot_f_distribution(df1, df2, alpha=0.05): # Create x values for the plot x = np.linspace(0, 5, 1000) # Calculate F-distribution values y = stats.f.pdf(x, df1, df2) # Calculate critical F-value f_crit = stats.f.ppf(1 – alpha, df1, df2) # Create the plot plt.figure(figsize=(10, 6)) # Add solid black … Read more
This tutorial shows how to create OpenAI website style illustrations using Python Turtle graphics. The following includes two examples. Example 1: Parallel Lines The following is the first example of drawing an OpenAI-style figure using Python Turtle. If you run the code, you will get the following figure, which includes some parallel lines with different … Read more
This tutorial shows how you can calculate p-value for linear regression. It includes formulas and data examples in Python. Formulas for p-value in Linear Regression We can estimate the regression coefficient B using the following formula. Where, Such calculation only generates regression coefficients but no p-values. To calculate the p-value, you need to calculate the … Read more
This tutorial compares t-distribution and normal distribution by explaining the similarities and connections between t-distribution and normal distribution. Similarities between t-distribution and normal distribution There are a few similarities between t-distribution and normal distribution. The following figure shows the t-distribution density function curve and the standard normal curve. As we can see, as the sample … Read more
The 2 popular Python packages for hypothesis testing are scipy.stats and statsmodels. The following includes a brief introduction to each of them, along with simple examples. Introduction of Scipy.stats Based on scipy.stats official webpage, the module contains a large number of probability distributions, summary and frequency statistics, correlation functions and statistical tests, and more. Example … Read more
Definition of Hypothesis Testing Hypothesis Testing is an inferential statistical method using sample data to solve assumptions about population parameters (characteristics that describe a population). For instance, you want to test if people in New York City’s attitudes toward the new iPhone (e.g., iPhone 14) on a 7-point scale (1 = not at all, 7 = like … Read more
There are 2 methods of changing the column names of Pandas Dataframes. The following shows the basic Python code syntax for changing column names of Pandas Dataframes. Method 1: df.rename(columns={‘old_name_1′:’new_name_1’, ‘old_name_2′:’new_name_2’}, inplace=True) Method 2: df = df.rename({‘old_name_1′:’new_name_1’, ‘old_name_2′:’new_name_2’}, axis=1) Example 1 of changing column names of Pandas DataFrames (Method 1) The following is the first … Read more
You can use Numpy column_stack() or row_stack() to combine lists into an array. As Columns: np.column_stack((list1, list2,…)) As Rows: np.row_stack((list1, list2,…)) Example 1 of lists to columns The following combines lists into an array using column_stack(). Thus, lists become columns in the array. [[6 2 4] [2 1 1] [3 3 2] [4 4 4] … Read more
This tutorial shows examples of checking if an item is in a Python list. Method 1: item in list_name Method 2: list_name.index(item) Method 3: list_name.count(item) Example for method 1: Check if an item in a list The following code checks if the item of number 6 is in a list. The following is the output, … Read more
This tutorial uses 2 examples to show how to count the number of NaN in Pandas dataframes. Method 1: count the number of NaN by columns: df.isnull().sum() Method 2: count the number of NaN in the whole dataframe: df.isnull().sum().sum() Example for Method 1 The following counts the number of NaN by columns using df.isnull().sum(). The … Read more