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Machine Learning

Algorithms that learn patterns from data.

Machine learning algorithms fit models to examples so they can predict, classify, cluster, or transform new data.

Machine LearningO(ndt)

Linear Regression

Fits a linear model that predicts a numeric target from input features.

BeginnerFoundationFormula11 links
Machine LearningSupervised LearningRegressionOptimization
Machine LearningO(ndt)

Logistic Regression

Models class probability by applying a logistic function to a linear score.

BeginnerFoundationFormula5 links
Machine LearningSupervised LearningClassificationOptimization
Machine LearningO(nkt)

K-Means

Clusters points by alternating between assigning points to nearest centroids and updating those centroids.

BeginnerFoundationFormula7 links
Machine LearningUnsupervised LearningClusteringIterative
Machine LearningO(n d log n)

Decision Tree

Predicts by recursively splitting examples with feature tests into simpler subgroups.

BeginnerFoundationFormula6 links
Machine LearningSupervised LearningClassificationTree
Machine LearningO(t n d log n)

Random Forest

Builds an ensemble of decision trees trained on random samples and feature subsets.

IntermediateCoreFormula5 links
Machine LearningEnsembleClassificationTree
Machine LearningO(w)

Backpropagation

Computes neural-network gradients by applying the chain rule backward through layers.

AdvancedFoundationFormula12 links
Machine LearningNeural NetworksOptimization
Machine LearningO(n log n)

DBSCAN

Clusters points by dense neighborhoods and labels sparse points as noise.

IntermediateCoreFormula2 links
Machine LearningClusteringDensity BasedUnsupervised Learning
Machine LearningO(nd)

K-Nearest Neighbors

Predicts from the labels or values of the closest training examples.

BeginnerCoreFormula1 links
Machine LearningNearest NeighborClassification
Machine LearningO(nd)

Naive Bayes

Classifies examples using feature probabilities and a simplifying independence assumption.

BeginnerCoreFormula2 links
Machine LearningClassificationSupervised Learning
Machine LearningO(nd^2 + d^3)

Principal Component Analysis

Projects data onto orthogonal directions that capture the largest variance.

IntermediateCoreFormula7 links
Machine LearningDimensionality ReductionLinear Algebra
Machine LearningO(n^2 d)

Support Vector Machine

Learns a separating decision boundary by maximizing the margin around support vectors.

IntermediateCoreFormula4 links
Machine LearningClassificationSupervised LearningOptimization
Machine LearningO(n d^2)

Ridge Regression

Fits linear regression with an L2 penalty that shrinks coefficients.

IntermediateCoreFormula5 links
Machine LearningRegressionSupervised LearningRegularization
Machine LearningO(k n d)

Lasso Regression

Fits a linear model while encouraging some weights to become exactly zero.

IntermediateCoreFormula8 links
Machine LearningRegressionSupervised LearningRegularization
Machine LearningO(k n d)

Elastic Net

Combines L1 and L2 penalties for sparse but more stable linear models.

IntermediateCoreFormula3 links
Machine LearningRegressionSupervised LearningRegularization
Machine LearningO(i n k d^2)

Gaussian Mixture Model

Models data as a weighted blend of several Gaussian distributions.

AdvancedExtendedFormula6 links
Machine LearningClusteringUnsupervised LearningEstimation
Machine LearningO(i n^2)

t-SNE

Embeds high-dimensional points into two or three dimensions while preserving local neighborhoods.

AdvancedSpecializedFormula3 links
Machine LearningDimensionality ReductionManifold LearningVisualization
Machine LearningO(e n d)

Perceptron

Learns a linear binary classifier by updating weights after mistakes.

BeginnerCoreFormula3 links
Machine LearningClassificationSupervised LearningNeural Networks
Machine LearningO(e n P)

Multilayer Perceptron

Uses stacked fully connected layers and nonlinear activations to learn flexible functions.

IntermediateCoreFormula4 links
Machine LearningNeural NetworksSupervised LearningOptimization
Machine LearningO(n^2 d)

Transformer Attention

Lets each token combine information from other tokens using learned query, key, and value vectors.

AdvancedSpecializedFormula2 links
Machine LearningNeural NetworksAttentionSequence Alignment
Machine LearningO(transitions)

Q-Learning

Learns action values from rewards without needing a model of the environment.

IntermediateSpecializedFormula4 links
Machine LearningReinforcement LearningOptimizationDynamic Programming
Machine LearningO(n k d)

Softmax Classifier

Classifies examples by turning linear class scores into probabilities.

IntermediateCoreFormula6 links
Machine LearningClassificationSupervised LearningLoss Function
Machine LearningO(n k)

Cross-Entropy Loss

Measures how well predicted probabilities match the true class distribution.

BeginnerFoundationFormula4 links
Machine LearningLoss FunctionClassificationSupervised Learning
Machine LearningO(layers * k h w)

Convolutional Neural Network

Learns local filters that detect patterns across grid-like data such as images.

AdvancedCoreFormula4 links
Machine LearningNeural NetworksImage ProcessingSupervised Learning
Machine LearningO(T h^2)

Recurrent Neural Network

Processes sequences by carrying hidden state from one step to the next.

AdvancedCoreFormula8 links
Machine LearningNeural NetworksSequence ModelingSupervised Learning
Machine LearningO(T h^2)

Long Short-Term Memory

Uses gates and a memory cell to model longer sequence dependencies.

AdvancedCoreFormula4 links
Machine LearningNeural NetworksSequence ModelingGating
Machine LearningO(T h^2)

GRU

Models sequences with gated hidden-state updates using fewer gates than LSTM.

AdvancedCoreFormula4 links
Machine LearningNeural NetworksSequence ModelingGating
Machine LearningO(n * parameters)

Autoencoder

Learns a compact representation by reconstructing its input.

IntermediateCoreFormula3 links
Machine LearningUnsupervised LearningNeural NetworksDimensionality Reduction
Machine LearningO(n * parameters)

Variational Autoencoder

Learns a probabilistic latent space that can reconstruct and generate examples.

AdvancedExtendedFormula3 links
Machine LearningUnsupervised LearningNeural NetworksProbabilistic Model
Machine LearningO(t n log n)

Gradient Boosting

Builds an ensemble by adding weak models that reduce current prediction error.

IntermediateCoreFormula7 links
Machine LearningEnsembleBoostingSupervised Learning
Machine LearningO(t n)

AdaBoost

Builds a classifier by reweighting examples that previous weak learners misclassified.

IntermediateCoreFormula3 links
Machine LearningEnsembleBoostingClassification
Machine LearningO(t n log n)

XGBoost-Style Gradient Boosted Trees

Trains regularized boosted decision trees using gradient and curvature information.

AdvancedExtendedFormula3 links
Machine LearningEnsembleBoostingDecision Tree
Machine LearningO(candidate_count * n)

Apriori Algorithm

Finds frequent itemsets by expanding only candidates whose subsets are frequent.

IntermediateExtendedFormula1 links
Machine LearningAssociation RulesFrequent ItemsetData Mining
Machine LearningO(T S^2)

Hidden Markov Model

Models sequences with hidden states that emit observed values over time.

AdvancedCoreFormula2 links
Machine LearningProbabilistic ModelSequence ModelingMarkov Chain
Machine LearningO(n log n)

UMAP

Embeds high-dimensional data into a lower-dimensional layout that preserves local neighborhoods.

AdvancedExtendedFormula3 links
Machine LearningDimensionality ReductionManifold LearningNearest Neighbor
Machine LearningO(n d t)

Gaussian Naive Bayes

Gaussian Naive Bayes learns a predictive, clustering, representation, or policy model from data.

IntermediateCoreFormula1 links
Machine Learning
Machine LearningO(n d t)

Multinomial Naive Bayes

Multinomial Naive Bayes learns a predictive, clustering, representation, or policy model from data.

IntermediateCoreFormula1 links
Machine Learning
Machine LearningO(n d t)

Extra Trees

Extra Trees learns a predictive, clustering, representation, or policy model from data.

IntermediateCoreNo formula2 links
Machine Learning
Machine LearningO(n d t)

Isolation Forest

Isolation Forest learns a predictive, clustering, representation, or policy model from data.

IntermediateCoreFormula1 links
Machine Learning
Machine LearningO(n d t)

One-Class SVM

One-Class SVM learns a predictive, clustering, representation, or policy model from data.

IntermediateSpecializedNo formula1 links
Machine Learning
Machine LearningO(n d t)

Self-Organizing Map

Self-Organizing Map learns a predictive, clustering, representation, or policy model from data.

IntermediateSpecializedFormula1 links
Machine Learning
Machine LearningO(n d t)

Learning Vector Quantization

Learning Vector Quantization learns a predictive, clustering, representation, or policy model from data.

IntermediateSpecializedFormula1 links
Machine Learning
Machine LearningO(n d t)

Label Propagation

Label Propagation learns a predictive, clustering, representation, or policy model from data.

IntermediateCoreFormula1 links
Machine Learning
Machine LearningO(n d t)

Policy Gradient

Policy Gradient learns a predictive, clustering, representation, or policy model from data.

IntermediateCoreFormula2 links
Machine Learning
Machine LearningO(n d t)

Actor-Critic Method

Actor-Critic Method learns a predictive, clustering, representation, or policy model from data.

IntermediateCoreFormula2 links
Machine Learning
Machine LearningO(n^3)

Gaussian Process Regression

Predicts a continuous target with a Gaussian process posterior over functions.

IntermediateCoreFormula3 links
Machine Learning
Machine LearningO(n^3)

Gaussian Process Classification

Gaussian Process Classification addresses bayesian classification by using a Gaussian process latent function with a classification likelihood.

IntermediateExtendedNo formula2 links
Machine Learning
Machine LearningO(k^2)

Matrix Factorization

Approximates a data matrix as a product of lower-dimensional latent factor matrices.

IntermediateCoreNo formula4 links
Machine LearningLinear Algebra
Machine LearningO(n log n)

Word2Vec Skip-Gram

Learns word embeddings by predicting nearby context words from a center word.

IntermediateCoreNo formula2 links
Machine Learning