Useful Links
Mathematics
Statistics
Regression Analysis
Linear Regression
Simple Linear Regression
Definition and Purpose
Mathematical Representation
Two-variable Equation: y = b0 + b1x + e
Parameters: b0 (intercept), b1 (slope), e (error term)
Data Fitting
Least Squares Method
Interpretation of Coefficients
Visualization
Scatter Plots with Regression Line
Applications and Examples
Multiple Linear Regression
Definition and Purpose
Mathematical Representation
Multi-variable Equation: y = b0 + b1x1 + b2x2 + ... + bnxn + e
Importance of Multicollinearity
Detection (Variance Inflation Factor)
Remedies (Ridge Regression, Variable Selection)
Assumptions
Linearity
Independence
Homoscedasticity (constant variance of errors)
Normality of error terms
Diagnostics
Residual Analysis
Cook's Distance for Influential Points
Durbin-Watson Test for Autocorrelation
Model Interpretation
Coefficient Significance
R-Squared and Adjusted R-Squared
Visualization
Residual Plots
Partial Regression Plots
Non-linear Regression
Introduction and Use Cases
Models
Polynomial Regression
Logistic Function for S-curve Fitting
Estimation Methods
Iterative Approximation (e.g., Newton-Raphson)
Convergence Criteria
Assumptions and Diagnostics
Error Term Behavior
Model Fit Analysis
Logistic Regression
Purpose and Applications
Binary Outcome Variables
Odds and Log Odds
Mathematical Representation
Logit Function: log(p/(1-p)) = b0 + b1x1 + b2x2 + ... + bnxn
Extensions
Multinomial Logistic Regression
Ordinal Logistic Regression
Model Evaluation
Confusion Matrix
ROC Curve and AUC
Assumptions
Linearity of Logits
Independence of Errors
Absence of Multicollinearity
Correlation and Causation
Correlation Coefficient (Pearson's r)
Strength and Direction of Linear Relationship
Testing Significance
Limitations of Correlation
Correlation does not imply causation
Spurious Correlations
Causation Analysis
Granger Causality
Structural Equation Modeling (SEM)
Model Selection Techniques
Criteria for Model Selection
Akaike Information Criterion (AIC)
Bayesian Information Criterion (BIC)
Stepwise Regression
Forward Selection
Backward Elimination
Bidirectional Elimination
Regularization Methods
Lasso Regression
Ridge Regression
Cross-Validation
k-Fold Cross-Validation
Leave-One-Out Cross-Validation (LOOCV)
Considerations for Overfitting
Balancing Complexity and Generalization
4. Probability Theory
First Page
6. Multivariate Statistics