In our previous discussions about Linear Regression (and the OLS Estimator), we identified a key limitation: multicollinearity. When the predictor variables (columns of $latex X$) are highly correlated, the matrix $latex X^{T}X$ becomes nearly singular, affecting the stability of our OLS estimator. Ridge Regression effectively addresses the limitations of OLS regression by incorporating a parameter … Continue reading Advanced – Ridge Regression Notes (Module 1)
Advanced – MAP Estimation using Simulated Annealing
In the preceding sections, we covered the intricacies of Linear Regression, explored the concept of Maximum Likelihood Estimation (MLE), and further dissected the statistical properties of the OLS estimator. Having laid some groundwork with earlier topics, the next step involves a thorough examination of MAP estimation. Both MLE and MAP are referred to as point … Continue reading Advanced – MAP Estimation using Simulated Annealing
Advanced – A Closer Look at the OLS Estimator
Understanding how our estimators behave is crucial for making accurate predictions. In my blog about Linear Regression, we covered the OLS estimator, which characterizes the weight vector of our linear regression model in terms of $latex X$ and $latex y$: $latex w_{LS} = (X^{T}X)^{-1}X^{T}y$ In many practical situations, we assume that $latex y$ is drawn … Continue reading Advanced – A Closer Look at the OLS Estimator
Advanced – Linear Regression
Linear regression serves as a fundamental stepping stone into the world of machine learning, embodying both simplicity and the power of predictive analytics. Conceptually, it rests on a graceful mathematical framework that elegantly unravels its potential and delineates its limitations. This guide will walk you through the mathematical fundamentals, offering a clear exposition of its foundational … Continue reading Advanced – Linear Regression
Advanced – Maximum A Posteriori Estimation Decoding
(Part One: AWGN Model) A useful example of MAP estimation was NASA's 1997 US patent, pertaining to the invention of a MAP decoder for digital communications. MAP decoding is a probabilistic decoding method that selects the most likely transmitted sequence given the received sequence and the channel's statistical properties. It is fundamental in the field … Continue reading Advanced – Maximum A Posteriori Estimation Decoding
Advanced – Maximum Likelihood Estimation
In statistical inference, one often encounters a dataset $latex X = \{x_1, x_2, \ldots, x_k\} \subset \mathbb{R}^n$ and seek to characterize it by estimating the parameters $latex \theta$ of a chosen probability distribution $latex p(X | \theta)$. A prevalent technique for achieving this is Maximum Likelihood Estimation (MLE). At its core, MLE is the method … Continue reading Advanced – Maximum Likelihood Estimation