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
The following is the core R syntax to do one sample t-test in R. In particular, Method 1 uses built-in R function, whereas method 2 writes the function to test one sample t-test in R from scratch. Method 1: t.test(vector_name, mu = value_to_compare, alternative = “two.sided”) Method 2: (mean(vector_name)-value_to_compare)/(sd(vector_name)/sqrt(number_of_observation)) Data Example for One Sample t-test … Read more
This tutorial shows how to plot interactions of 2 categorical independent variables in Python. The following shows both the ANOVA and linear regression outputs. You will see that ANOVA is also a linear regression model. Thus, it does not matter you use ANOVA or linear regression, you can use the same method (i.e., the same … Read more
This tutorial shows how you can calculate predicted Y (or, estimated Y) in linear regression in Python. Steps of Calculating Predicated Y in Linear Model in Python Step 1: Prepare data, X and Y Output: X: [[ 5] [ 2] [ 3] [ 4] [10] [11] [14]] Y: [[ 3] [ 1] [ 2] [ … Read more
This tutorial shows how you can conduct linear regression Python Numpy from scratch. 1. Math and Matrix of Linear Regression We can use just use pure matrix calculation to estimate the regression coefficients in a linear regression model. Below is the process. Thus, we can simplify the function above to the function below. We can … Read more
1. Introduction Type I, Type II, and Type III ANOVA are 3 different ways of calculating sum of squares in ANOVA. Type I ANOVA: SS(A) for factor A SS(B | A) for factor B SS(AB | A, B) for interaction AB Type II ANOVA: SS(A | B) for factor A SS(B | A) for factor … Read more
Introduction We can use sklearn.linear_model.LinearRegression to do linear regression in Python. The following is the core syntax of using sklearn. lm.fit(IVs, DV) Where, IVs: the independent variables DV: the dependent variable Example for Linear Regression Model The following is the linear regression model, including household income as IVs and purchase intention as DV. The following … Read more
This tutorial shows how you can remove stop words using nltk in Python. Stop words are words not carrying important information, such as propositions (“to”, “with”), articles (“an”, “a”, “the”), or conjunctions (“and”, “or”, “but”). We first need to import the needed packages. We can then set the language to be English. Before removing stop … Read more
One-Way ANOVA is to compare the means of different groups, to see whether the mean difference is statistically significant. For instance, you would like to compare the average household size of three cities. You can collect 3 samples from these three cities and conduct a one-way ANOVA to check the difference. Formulas of One-way ANOVA … Read more
What is Correlation? Correlation is a statistical measure of the relationship between two variables, X and Y. For instance, you can measure to what extent temperature (X) is related to the production of ice cream (Y). You probably would expect that higher temperatures correspond with higher production of ice cream. On the plot shown below, … Read more