Tagged “classification”

3 articles.

9 September 202610 min readSupervised Learning

Comparing Classifiers, and What Accuracy Hides

The Bayes classifier nothing can beat and the error floor it leaves behind, k-nearest-neighbours as a nonparametric imitation with k as the flexibility dial, discriminant analysis and why a shared covariance forces a straight line, and the confusion matrix, thresholds and ROC curve that a single accuracy figure conceals - every number computed on simulated data where the optimum is known.

Machine LearningStatistics

8 September 20267 min readSupport Vector Machines

Support Vector Machines: Margins and Kernels

Why the widest slab between two classes is a good boundary, why insisting on a perfect one is self-defeating, how a budget for violations buys back stability, and how a kernel bends the boundary by working in a space it never has to build.

Machine LearningOptimization

24 August 20267 min readSupervised Learning

Logistic Regression and Classification

Why a straight line cannot model a probability, how the logistic function fixes it, and what the coefficients mean in log-odds, with a gradient-ascent step and a converged fit computed and checked numerically.

StatisticsMachine LearningOptimization