Explorations
323 interactive essays to build intuition.
Algebra
6 explorationsComplex Numbers
ExplorationExplore complex number operations and visualize them on the complex plane
Function Transformations Explorer
ExplorationUnderstand how vertical shifts, horizontal shifts, stretches, compressions, and reflections transform the graphs of functions
Polynomial Behavior Explorer
ExplorationUnderstand end behavior, zeros, and turning points of polynomials
Quadratic Explorer
ExplorationUnderstand parabolas through vertex form, roots, and the discriminant
Systems of Equations Explorer
ExplorationVisualize solutions to systems of linear equations as intersection points
Understanding Slope: Rise Over Run
ExplorationBuild intuition for what slope means through interactive exploration of steepness, direction, and rate of change
Art
1 explorationBiology
1 explorationCalculus
17 explorationsDerivatives
4Derivative Explorer
ExplorationVisualize the relationship between a function and its derivative through synchronized graphs and tangent lines
Derivative Visualizer
ExplorationExplore functions, derivatives, and tangent lines interactively with 8 common functions
Optimization Explorer
ExplorationFind maximum and minimum values using derivatives
Related Rates Explorer
ExplorationVisualize how changing one quantity affects another through derivatives
Integration
5Area Between Curves
ExplorationVisualize and calculate the area enclosed between two functions
Integral Calculator
ExplorationVisualize definite integrals and compare Riemann sum approximation methods
Monte Carlo Integration
ExplorationUse random sampling to estimate definite integrals - watch probability converge to calculus
Riemann Sums Comparison
ExplorationCompare left, right, midpoint, and trapezoidal methods side-by-side on a single function to see which converges fastest
Riemann Sums and Numerical Integration
ExplorationVisualize left, right, midpoint, and trapezoidal approximations for any function on any interval
Limits & Continuity
3Epsilon-Delta Limit Explorer
ExplorationInteractively explore the formal epsilon-delta definition of limits and understand how epsilon and delta relate
Limit Explorer
ExplorationVisualize limits, one-sided limits, and continuity for functions with removable, jump, and infinite discontinuities
Understanding Limits and Continuity
ExplorationExplore how functions behave as they approach specific values and what makes a function continuous
Multivariable
3Gradient Descent Visualization
ExplorationVisualize gradient vectors on a loss surface to understand how gradient descent finds minima
Gradient Vector Field Visualizer
ExplorationExplore gradient vector fields, contour plots, and gradient descent optimization for multivariable functions
Potential Energy Surface
ExplorationExplore an energy landscape with critical points, showing minima, maxima, and saddle points
Chemistry
6 explorationsAtomic Orbitals
ExplorationExplore electron configuration, orbital shapes, and how electrons fill atomic orbitals according to quantum mechanics
Ideal Gas Law
ExplorationExplore the ideal gas law PV = nRT and understand the relationships between pressure, volume, temperature, and amount of gas
Molecular Geometry (VSEPR Theory)
ExplorationExplore how electron pairs determine molecular shapes using VSEPR theory, and understand the relationship between geometry, bond angles, and polarity
pH Scale
ExplorationExplore the pH scale and understand how hydrogen ion concentration determines acidity and basicity
Radioactive Decay
ExplorationExplore radioactive decay and understand how half-life determines the rate at which unstable atoms transform over time
States of Matter - Phase Diagrams
ExplorationExplore how temperature and pressure determine the state of matter using interactive phase diagrams
Complex Analysis
2 explorationsComputer Science
47 explorationsAlgorithms & Complexity
8Algorithm Visualization with Flowcharts
ExplorationStep through common algorithms with interactive flowcharts showing decision structures, loops, and execution paths
Big-O Complexity
ExplorationCompare algorithm time complexities and see how different Big-O classes scale with input size
Big-O Complexity Quiz
ExplorationMaster algorithm complexity analysis by exploring time complexity, growth rates, and classifying algorithms into Big-O categories
Big O Notation Visualizer
ExplorationCompare time complexities across different algorithm classes and understand asymptotic behavior
Fibonacci Recursion Tree
ExplorationStep through the execution of the Fibonacci function to visualize recursion, understand exponential complexity, and see how memoization optimizes performance
Recursion Depth and Complexity
ExplorationVisualize recursive call patterns, stack depth, and memoization benefits
Sorting Algorithm Comparison
ExplorationStep through bubble sort, selection sort, and insertion sort to understand how different sorting algorithms work and compare their efficiency
Sorting Algorithm Comparison
ExplorationCompare time complexity and operations for classic sorting algorithms
Automata & Logic
4Boolean Logic & Digital Circuits
ExplorationExplore Boolean algebra, logic gates, and digital circuit design with interactive truth tables and circuit diagrams
Finite State Machines
ExplorationExplore finite state machines (FSMs) - fundamental models of computation used in software design, hardware, and digital systems
Regular Expression Automata
ExplorationVisualize how regular expressions are processed by finite automata - step through string matching character by character
Regular Expression Concepts
ExplorationExplore regular expression pattern matching, character classes, quantifiers, and the state machines that power regex engines
Cryptography & Security
5Caesar Cipher Analysis
ExplorationExplore the classic substitution cipher and understand why simple encryption is vulnerable
Digital Signature Security
ExplorationUnderstand how digital signatures provide authentication, integrity, and non-repudiation
Symmetric vs Asymmetric Encryption
ExplorationCompare encryption methods and understand their tradeoffs in security and performance
Cryptographic Hash Functions
ExplorationExplore hash function properties including collision resistance and preimage resistance
Password Strength Calculator
ExplorationAnalyze password entropy, crack time, and security against brute force attacks
Data Structures
5Binary Search Tree Analysis
ExplorationExplore BST operations and understand how tree balance affects search performance
Binary Search Trees
ExplorationExplore binary search trees and understand tree traversal algorithms through interactive visualization
Linked List Cycle Detection
ExplorationExplore Floyd's cycle detection algorithm (tortoise and hare) to detect cycles in linked lists
Hash Table Performance Analysis
ExplorationUnderstand load factors, collision probability, and hash table efficiency
Linked List Operations
ExplorationExplore linked list data structures and understand common operations like traversal, insertion, and deletion
Graph Algorithms
6Graph Traversal Algorithms
ExplorationExplore BFS and DFS traversal strategies and their time/space complexity on graphs
Minimum Spanning Tree
ExplorationExplore Kruskal's and Prim's algorithms for finding minimum spanning trees in weighted graphs
Network Flow
ExplorationExplore maximum flow problems and the Ford-Fulkerson algorithm in flow networks
Shortest Path Algorithms
ExplorationCompare Dijkstra's and Bellman-Ford algorithms for finding shortest paths in weighted graphs
Topological Sort
ExplorationExplore topological ordering of directed acyclic graphs (DAGs) with Kahn's algorithm
Traveling Salesman Problem
ExplorationExplore the TSP, exact vs heuristic solutions, and the complexity of combinatorial optimization
Image Processing
4Histogram Equalization
ExplorationUnderstand how histogram equalization enhances image contrast by remapping intensity distributions using the cumulative distribution function
Image Compression Fundamentals
ExplorationExplore how JPEG-style compression works, understand the tradeoff between quality and file size, and learn about DCT quantization
Image Convolution Filters
ExplorationLearn how convolution kernels transform images through blur, sharpen, and edge detection operations
Morphological Image Operations
ExplorationExplore erosion, dilation, opening, and closing operations on binary images using structuring elements
Information Theory
4Shannon Channel Capacity
ExplorationCalculate the maximum data rate of a communication channel using Shannon's channel capacity theorem
Data Compression Analysis
ExplorationAnalyze compression ratios, space savings, and theoretical entropy bounds for data compression
Shannon Entropy Calculator
ExplorationCalculate information entropy and understand uncertainty quantification in probability distributions
Huffman Coding Analysis
ExplorationAnalyze Huffman coding efficiency for optimal prefix-free compression codes
Natural Language Processing
5N-gram Frequency Analyzer
ExplorationExplore how text can be decomposed into n-grams (unigrams, bigrams, trigrams) and analyze their frequency distributions
Sentiment Analysis
ExplorationExplore lexicon-based sentiment analysis and understand how word scores combine to determine the emotional tone of text
Text Tokenizer & Stemmer
ExplorationExplore text tokenization, the Porter Stemming algorithm, and word frequency statistics used in natural language processing
TF-IDF Calculator
ExplorationExplore Term Frequency-Inverse Document Frequency, the foundational text weighting scheme used in information retrieval and text mining
Word Embeddings
ExplorationExplore word vector representations, cosine similarity, and vector arithmetic in word embedding spaces
Optimization
3Constraint Satisfaction Problems
ExplorationExplore CSPs, backtracking search, and constraint propagation for solving puzzles and scheduling problems
Knapsack Problem
ExplorationExplore the 0/1 knapsack problem with dynamic programming and greedy approximation
Linear Programming
ExplorationExplore linear optimization with two decision variables, constraints, and the simplex method
Randomness
2RNG Algorithm Comparator
ExplorationCompare pseudo-random number generators (LCG, Mersenne Twister, xorshift) by their period, state space, and statistical quality
RNG Test Suite
ExplorationApply statistical tests to evaluate random number generator quality using frequency tests, runs tests, and chi-square analysis
Data Science
19 explorationsExploratory Analysis
6Comparing Distributions with Box Plots
ExplorationVisualize and compare multiple datasets using box plots and five-number summaries
Exploratory Data Analysis
ExplorationExplore and visualize data distributions using dot plots and stem-and-leaf plots
Interactive Scatter Plot
ExplorationLearn to explore data by creating, moving, and analyzing points in real-time
Percentiles and Quartiles
ExplorationUnderstand data position with percentiles, quartiles, and the interquartile range
Back-to-Back Stem-and-Leaf Plots
ExplorationCompare two distributions side-by-side using back-to-back stem-and-leaf plots
Understanding Variance and Standard Deviation
ExplorationExplore how variance and standard deviation measure the spread of data
ML Preprocessing
6Cross-Validation Techniques
ExplorationLearn k-fold, stratified, and leave-one-out cross-validation for robust model evaluation
Feature Scaling for Machine Learning
ExplorationUnderstand standardization, normalization, and why feature scaling matters for ML algorithms
Gradient Descent Optimization
ExplorationExplore how gradient descent finds function minima by iteratively following the steepest descent direction
Outlier Detection Methods
ExplorationLearn IQR, z-score, MAD, and isolation forest methods for detecting outliers in data
Principal Component Analysis (PCA)
ExplorationVisualize how PCA finds directions of maximum variance and projects data onto principal components
Train-Test Split
ExplorationUnderstand how to split data for model training and evaluation, including stratification and random state
Probability
4Birthday Paradox
ExplorationExplore the surprising probability that two people share a birthday
Probability with Events and Sample Spaces
ExplorationExplore probability concepts including union, intersection, complement, conditional probability, and independence using visual representations of events within a sample space
Probability Trees and Bayes' Theorem
ExplorationUse probability trees to understand conditional probability and medical test accuracy
Set Operations & Probability
ExplorationExplore the relationship between set theory and probability using Venn diagrams and the Addition Rule
Regression
3Correlation Explorer
ExplorationVisualize and understand correlation strength and direction
Linear Regression Explorer
ExplorationUnderstand how least squares regression finds the best-fit line
Logistic Regression Explorer
ExplorationVisualize binary classification with the sigmoid function, decision boundary, and probability predictions
Discrete Math
6 explorationsBinary Numbers
ExplorationExplore how decimal numbers are represented in binary using powers of 2
Convex Hull Algorithm
ExplorationExplore convex hulls in computational geometry - understand the Graham scan algorithm, cross products for orientation testing, and how hull size relates to point distributions
Game Theory Decision Trees
ExplorationExplore extensive form games and learn backward induction to find optimal strategies
Graph Coloring and Chromatic Number
ExplorationExplore proper vertex coloring, the chromatic number, greedy coloring, and the Four Color Theorem through interactive graph examples
Graph Theory Basics
ExplorationLearn the fundamentals of graph theory through interactive visualizations - vertices, edges, degrees, paths, and special graph types
Modular Arithmetic
ExplorationExplore clock arithmetic and modular operations with visual representations on a circle
Distributions
11 explorationsThe Binomial Distribution
ExplorationExplore probability of successes in repeated independent trials
Bivariate Normal Distribution
ExplorationExplore the 2D Gaussian distribution with correlation
Understanding the Central Limit Theorem
ExplorationExplore how sample means distribute normally regardless of population distribution
The Chi-Square Distribution
ExplorationExplore the chi-square distribution, its relationship to the normal distribution, and applications in hypothesis testing
Comparing Distributions with Box Plots
ExplorationLearn to compare and interpret distributions using interactive box plots
Distribution Visualizer
ExplorationVisualize and compare properties of Normal, Binomial, Poisson, Uniform, and Exponential distributions
The Exponential Distribution
ExplorationExplore the exponential distribution, its memoryless property, and relationship to the Poisson process
Normal Distribution Properties
ExplorationExplore the properties of the normal distribution including shape parameters, the empirical rule, z-scores, and probability calculations
The Poisson Distribution
ExplorationModel the probability of rare events occurring in a fixed interval
The t-Distribution
ExplorationExplore the Student's t-distribution and understand when to use it instead of the normal distribution
The Uniform Distribution
ExplorationExplore the continuous and discrete uniform distributions, their properties, and probability calculations
Economics
2 explorationsEngineering
8 explorationsStructural Beam Analysis
ExplorationAnalyze simply supported beams using static equilibrium principles
Beam Deflection Analysis
ExplorationVisualize how beams bend under load and explore the relationship between material properties, geometry, and deflection
Circuit Analysis Explorer
ExplorationMaster series, parallel, and combination circuits with interactive visualizations of Ohm's Law, Kirchhoff's laws, and power dissipation
RC Filter Design
ExplorationDesign low-pass and high-pass filters using resistance-capacitance circuits
Pipe Flow & Pressure Drop
ExplorationExplore pipe flow, Reynolds number, and pressure drop using the Darcy-Weisbach equation
RC Circuit Time Constant
ExplorationExplore RC circuit charging and discharging behavior, time constants, and exponential voltage response
Nyquist-Shannon Sampling Theorem
ExplorationUnderstand sampling requirements, aliasing, and the Nyquist rate for digital signal processing
Spectral Analysis with FFT
ExplorationExplore frequency analysis using the Discrete Fourier Transform and Fast Fourier Transform algorithms
Everyday Math
7 explorationsCompound Discounts
ExplorationExplore how multiple discounts stack and discover the effective total discount
Data Size Converter
ExplorationConvert between bits, bytes, KB, MB, GB, TB, and PB in binary (1024) and decimal (1000) systems
Length Converter
ExplorationConvert between metric, imperial, and nautical length units with visual comparisons
Speed Converter
ExplorationConvert between mph, km/h, m/s, knots, and Mach with real-world speed comparisons
Temperature Converter
ExplorationConvert between Celsius, Fahrenheit, and Kelvin with reference points and conversion formulas
Tip Splitting
ExplorationCalculate how to split a restaurant bill with tip among friends
Weight Converter
ExplorationConvert between metric and imperial weight units with real-world comparisons
Finance
6 explorationsThe Power of Compound Growth
ExplorationExplore how compound interest grows your money over time
Compound Interest Explorer
ExplorationLong-term wealth visualization with monthly contributions and inflation adjustment
Currency Converter
ExplorationConvert between currencies, understand exchange rates, spreads, cross rates, and the cost of round-trip conversions
Loan Amortization
ExplorationExplore how loan payments are divided between principal and interest over time
Retirement Planner
ExplorationPlan your retirement savings with compound growth, calculate safe withdrawal rates, and estimate how long your money will last
Tax Brackets
ExplorationUnderstand the difference between marginal and effective tax rates using 2024 US federal brackets
Geometry
20 explorations3D Geometry
1Circles & Conics
4Arc Length & Sector Area Explorer
ExplorationCalculate arc length and sector area with real-world examples like pizza slices and clock hands
Circle Properties Explorer
ExplorationDiscover how radius, diameter, circumference, and area relate to each other
Conic Sections
ExplorationExplore circles, ellipses, parabolas, and hyperbolas through eccentricity, focus-directrix properties, and real-world applications
Inscribed Angles Explorer
ExplorationDiscover the relationship between inscribed and central angles in circles
Computational Geometry
4Closest Pair of Points
ExplorationExplore the divide-and-conquer algorithm for finding the closest pair of points in a plane
Delaunay Triangulation
ExplorationExplore Delaunay triangulation properties, the empty circumcircle condition, and its dual relationship with Voronoi diagrams
Line Intersection Detector
ExplorationExplore how two line segments intersect using parametric equations and cross products from computational geometry
Voronoi Diagrams
ExplorationExplore Voronoi tessellations, nearest-neighbor partitions, and Fortune's sweep line algorithm
Coordinate Geometry
4Geometric Transformations
ExplorationExplore how translations, rotations, reflections, and dilations transform shapes in the coordinate plane
The Golden Spiral
ExplorationExplore the beautiful golden spiral through Fibonacci rectangles and discover how ratios converge to φ
Polar Coordinates Explorer
ExplorationConvert between rectangular and polar coordinates, visualizing the relationship between (x, y) and (r, θ)
2D Vectors Explorer
ExplorationExplore vector operations including addition, scalar multiplication, and dot product
Fundamentals
7Angle Relationships Explorer
ExplorationExplore complementary, supplementary, vertical, and corresponding angles
Area of Polygons Explorer
ExplorationSee how all polygon areas relate to rectangles
Distance & Midpoint Explorer
ExplorationCalculate distance and midpoint between two points using coordinate geometry
Polygon Interior Angles
ExplorationDiscover why the interior angle sum of any polygon equals (n-2)×180°
Pythagorean Theorem Explorer
ExplorationVisualize a² + b² = c² with interactive area squares
Similar Triangles Explorer
ExplorationExplore triangle similarity through AA, SAS, and SSS criteria with interactive ratio relationships
Triangle Centers Explorer
ExplorationDiscover the centroid, incenter, circumcenter, and orthocenter of a triangle
History
1 explorationLinear Algebra
8 explorationsDot & Cross Product Calculator
ExplorationCalculate dot product, cross product, angle, and projection for 2D and 3D vectors
Eigenvalue Calculator
ExplorationCalculate eigenvalues and eigenvectors of 2×2 matrices with characteristic polynomial visualization
Eigenvalue Visualization
ExplorationVisualize eigenvectors and eigenvalues of 2x2 matrices - see how special vectors remain on their span under transformation
Linear Transformation Visualizer
ExplorationVisualize how 2×2 matrices transform space with determinant, trace, and transformation type analysis
Matrix Operations Explorer
ExplorationExplore matrix addition, multiplication, transpose, determinant, and inverse for 2×2 matrices
2D Matrix Transformations
ExplorationInteractive 2D transformation explorer - visualize how matrices transform space through scaling, rotation, shearing, and reflection
Singular Value Decomposition (SVD)
ExplorationVisualize how SVD decomposes any matrix into rotation, scaling, and another rotation - the fundamental factorization A = U*Sigma*V^T
SVD Demo
ExplorationExplore Singular Value Decomposition for 2×2 matrices with geometric interpretation
Machine Learning
24 explorationsCausal & Structural
1Classification
6Decision Trees
ExplorationExplore how decision trees make splits using Gini impurity and entropy, visualize decision boundaries, and understand the tradeoff between tree depth and overfitting
Linear Discriminant Analysis
ExplorationClassify observations and reduce dimensions using LDA
K-Nearest Neighbors Classification
ExplorationClassify points using majority voting from k nearest neighbors
Naive Bayes Classification
ExplorationLearn how Naive Bayes uses Bayes theorem with conditional independence to classify data
The Perceptron
ExplorationExplore the perceptron - a single artificial neuron as a linear classifier
Support Vector Machines
ExplorationUnderstand how SVMs find optimal decision boundaries using hyperplanes, margins, and support vectors
Clustering
2Ensemble Methods
2Gradient Boosting
ExplorationLearn how gradient boosting builds sequential ensemble models by iteratively fitting to residuals
Random Forests
ExplorationUnderstand how random forests combine multiple decision trees through bagging and feature randomization to create robust ensemble predictions
Evaluation
2Classification Metrics and Confusion Matrices
ExplorationLearn how to evaluate classification models using confusion matrices and key metrics like precision, recall, and F1 score
ROC Curves and AUC
ExplorationLearn how ROC curves visualize classifier performance and how AUC measures the probability that a classifier ranks positive examples higher than negative ones
Fundamentals
9Backpropagation
ExplorationStep through the forward and backward passes of a 2-layer neural network to see how gradients flow and weights update
The Bias-Variance Tradeoff
ExplorationUnderstand how model complexity affects underfitting, overfitting, and generalization error
Cross-Entropy Loss
ExplorationUnderstand binary and categorical cross-entropy loss functions and their relationship to maximum likelihood estimation
Feature Scaling Comparator
ExplorationCompare StandardScaler, MinMaxScaler, and RobustScaler to understand how each method transforms data for machine learning
Gradient Optimization Methods
ExplorationCompare gradient descent variants including SGD, momentum, Adam, and RMSProp for function optimization
Learning Rate Visualizer
ExplorationVisualize how the learning rate affects gradient descent convergence, oscillation, and divergence on different loss landscapes
Overfitting vs Underfitting
ExplorationUnderstand the bias-variance tradeoff and how model complexity affects generalization
Regularization in Machine Learning
ExplorationUnderstand L1 (Lasso), L2 (Ridge), and Elastic Net regularization to prevent overfitting
Train-Test Split Simulator
ExplorationVisualize how splitting a dataset into training and test sets affects model evaluation, and explore the tradeoffs between split ratios
Mathematical Statistics
14 explorationsOne-Way ANOVA
ExplorationCompare means across multiple groups using Analysis of Variance
Understanding Bayes' Theorem
ExplorationExplore how prior beliefs update with new evidence
Bayesian Inference
ExplorationExplore how prior beliefs combine with observed data to form posterior distributions using Bayes' theorem
Bootstrap Confidence Intervals
ExplorationLearn how resampling provides confidence intervals without parametric assumptions
Chi-Square Goodness of Fit Test
ExplorationTest whether observed frequencies match expected frequencies using the chi-square goodness of fit test
Chi-Square Test of Independence
ExplorationTest whether two categorical variables are related using a contingency table with visual highlighting of residuals
Confidence Intervals Explorer
ExplorationBuild intuition for what confidence intervals really mean through interactive visualizations
Effect Size - Cohen's d
ExplorationUnderstand practical significance through standardized effect sizes
Hypothesis Testing with t-Tests
ExplorationMaster one-sample and two-sample t-tests for comparing means when population variance is unknown
Hypothesis Testing Explorer
ExplorationVisualize and understand hypothesis testing with the one-sample z-test
The Law of Large Numbers
ExplorationWatch how sample averages converge to the true population mean as sample size grows
Maximum Likelihood Estimation
ExplorationLearn how to find the parameter values that make observed data most probable using the likelihood function
Sampling & Bias Explorer
ExplorationUnderstand how sampling methods affect statistical estimates
Statistical Power and Sample Size
ExplorationUnderstand the relationship between power, effect size, sample size, and significance level
Multivariate
4 explorationsCanonical Correlation Analysis
ExplorationExplore how CCA finds maximum correlations between two sets of variables through canonical variates
Factor Analysis Visualization
ExplorationUnderstand latent factors from observed variables through factor loadings, communalities, rotation, and simple structure interpretation
One-Way MANOVA
ExplorationExplore multivariate analysis of variance with group centroids, Wilks' Lambda, Pillai's trace, and F-approximation for comparing groups on multiple response variables
Principal Component Analysis Explorer
ExplorationExplore dimensionality reduction through PCA - understand loadings, variance explained, and how to visualize high-dimensional data in 2D
Number Theory
5 explorationsBase Converter
ExplorationConvert numbers between bases (binary, octal, decimal, hexadecimal) and understand positional notation
Fibonacci Explorer
ExplorationExplore the Fibonacci sequence, golden ratio convergence, Binet's formula, and mathematical identities
GCD & LCM Calculator
ExplorationCalculate GCD and LCM using the Euclidean algorithm with step-by-step visualization
Prime Factorization
ExplorationVisualize how numbers break down into their prime factors
Prime Finder
ExplorationDiscover prime numbers with the Sieve of Eratosthenes, primality testing, and prime factorization
Physics
19 explorationsElectromagnetism
1Mechanics
9Damped Oscillation
ExplorationExplore how a mass-spring system loses energy to friction over time
Energy Conservation
ExplorationExplore how potential and kinetic energy transform while total mechanical energy remains constant
Forces & Equilibrium
ExplorationExplore forces on an inclined plane and understand equilibrium conditions
Kinematics Explorer
ExplorationSee how position, velocity, and acceleration relate through derivatives
Orbital Mechanics
ExplorationExplore how a planet orbits a star following Kepler's laws
Phase Space Exploration
ExplorationExplore synchronized views of a simple harmonic oscillator showing position, velocity, and phase portrait
Advanced Projectile Motion
ExplorationExplore projectile motion with initial height, velocity components, and optimal launch angles
Simple Harmonic Motion
ExplorationExplore the fundamentals of simple harmonic motion - amplitude, period, frequency, displacement, and the connection to springs and pendulums
Simple Harmonic Motion - The Pendulum
ExplorationExplore the physics of a simple pendulum, including period, frequency, energy conservation, and the small angle approximation
Optics
4Double-Slit Interference Pattern
ExplorationExplore Young's famous double-slit experiment and discover how light creates interference patterns
Geometric Optics - Lenses and Mirrors
ExplorationExplore how lenses and mirrors form images using ray diagrams
Real vs Virtual Images
ExplorationUnderstand the difference between real and virtual images formed by lenses and mirrors
Wave Optics - Interference and Diffraction
ExplorationExplore the wave nature of light through interference and diffraction patterns, from single slits to diffraction gratings
Waves & Sound
4Audio Waveform Explorer
ExplorationExplore the relationship between frequency, amplitude, and waveform characteristics in audio signals
Fourier Transform Fundamentals
ExplorationExplore the relationship between time and frequency domains in signal analysis
Wave Superposition & Interference
ExplorationExplore how two wave sources create 2D interference patterns through constructive and destructive interference
Wave Superposition
ExplorationExplore how two sinusoidal waves combine through constructive and destructive interference, including beat frequency analysis
Psychometrics
5 explorationsClassical Test Theory
ExplorationExplore reliability as the ratio of true score variance to observed variance, including Cronbach's alpha, Spearman-Brown prophecy, and Standard Error of Measurement
Factor Loadings Matrix
ExplorationInterpret a factor loading matrix, understand communalities and uniqueness, and see how rotation affects loadings while preserving total variance
IRT Information Functions
ExplorationExplore how item and test information quantify measurement precision across the ability continuum
IRT: Item Characteristic Curves
ExplorationExplore how difficulty, discrimination, and guessing parameters shape the probability of a correct response in Item Response Theory
Measurement Error & True Score
ExplorationExplore the relationship between observed scores and true scores, understand standard error of measurement, and visualize regression to the mean
Statistics
42 explorationsAdvanced Tests
2Bayesian Methods
3Bayes' Theorem Calculator
ExplorationCalculate posterior probabilities using Bayes' theorem with prior, likelihood, and evidence
Bayesian Inference - Medical Testing
ExplorationUnderstand Bayes' theorem through medical testing scenarios and the base rate fallacy
Bayesian vs Frequentist Inference
ExplorationCompare Bayesian and frequentist approaches to statistical inference using Beta-Binomial conjugacy, prior sensitivity, and credible vs confidence intervals
Data Diagnostics
4Box-Cox Transformation Explorer
ExplorationExplore the Box-Cox power transformation to normalize skewed data and understand how lambda affects distribution shape
Missing Data Strategy Comparator
ExplorationCompare imputation methods (listwise deletion, mean, median, regression) and understand how missingness patterns affect statistical bias
Normality Test Suite
ExplorationAssess whether data follows a normal distribution using skewness, kurtosis, and statistical tests
Q-Q Plot Interpreter
ExplorationUnderstand Q-Q plots for assessing normality through quantile comparison
Descriptive Statistics
3Statistical Summary Explorer
ExplorationCompute descriptive statistics including mean, median, standard deviation, and quartiles
Statistics Quiz
ExplorationTest your understanding of core statistical concepts including mean, median, standard deviation, confidence intervals, and hypothesis testing
Univariate Explorer
ExplorationExplore univariate statistics including measures of central tendency, spread, distribution shape, and outlier detection using IQR, z-score, and modified z-score methods
Experimental Design
4Crossover Experimental Design
ExplorationDesign crossover trials where subjects receive multiple treatments in sequence, controlling for individual differences and carryover effects
Factorial Experimental Design
ExplorationDesign factorial experiments to study multiple factors simultaneously, estimate main effects and interactions, and optimize experimental efficiency
Random Sample Generator
ExplorationExplore simple random, systematic, and stratified sampling methods, and see how sample size and method affect coverage and representativeness
Randomization in Experimental Design
ExplorationCompare randomization strategies (CRD, RCBD, Latin Square) for controlling experimental error and improving precision
Hypothesis Testing
9A/B Test Calculator
ExplorationEvaluate A/B test results with z-tests for proportions, p-value calculations, minimum detectable effect, and sample size estimation
Hypothesis Test Calculator
ExplorationPerform one-sample and two-sample z-tests and t-tests with step-by-step calculations
Nonparametric Tests
ExplorationExplore nonparametric hypothesis tests including Mann-Whitney U and Wilcoxon signed-rank
P-Value Interpretation
ExplorationUnderstand what p-values really mean, common misconceptions, and the relationship between statistical and practical significance
Permutation Test
ExplorationExplore permutation (randomization) tests as a non-parametric alternative to t-tests, with no distributional assumptions required
Power Analysis
ExplorationVisualize statistical power through overlapping distributions, understand Type I and II errors, and determine required sample sizes for hypothesis tests
P-Value Misconceptions
ExplorationUnderstand what p-values really mean and explore common statistical misconceptions
Sample Size Calculator
ExplorationDetermine required sample sizes for hypothesis tests using power analysis
Type I and Type II Errors
ExplorationVisualize the tradeoff between false positives (alpha) and false negatives (beta), understand statistical power, and see how effect size and sample size influence error rates
Probability & Simulation
12Coin Flip Simulator
ExplorationExplore the Law of Large Numbers through coin flipping, seeing how observed proportions converge to the true probability as sample size grows
Dice Roller
ExplorationExplore dice probability, expected values, and how the Central Limit Theorem makes the sum of multiple dice approach a normal distribution
The Gambler's Fallacy
ExplorationUnderstand why past outcomes don't affect future probabilities in independent events, and why the belief that they do is one of the most persistent cognitive biases
Markov Chains
ExplorationExplore Markov chains - stochastic processes where the future depends only on the present, not the past
Monte Carlo Simulation
ExplorationExplore how random sampling estimates values through the Law of Large Numbers, with applications from estimating pi to option pricing
The Monty Hall Problem
ExplorationExplore the famous Monty Hall paradox through simulation, understanding why switching doors doubles your chance of winning
Probability Distribution Matcher
ExplorationGiven data characteristics like mean, standard deviation, skewness, and kurtosis, find which probability distribution best fits your data
Probability Distributions
ExplorationCompare and explore common probability distributions, their parameters, properties, and relationships
Random Walks and Diffusion
ExplorationExplore 1D random walks - how simple coin-flip steps lead to diffusion, Brownian motion, and the gambler's ruin problem
Randomness Visualizer
ExplorationExplore patterns in randomness, test for uniformity, and understand the chi-square test for random distributions
Simpson's Paradox
ExplorationDiscover how aggregated data can show the opposite trend from subgroup data, and learn to identify confounding variables
Synthetic Data Generator
ExplorationExplore how different probability distributions generate data, compare uniform, normal, exponential, and Poisson distributions, and understand their parameters and properties
Regression & Correlation
3Correlation Analysis
ExplorationExplore Pearson correlation coefficient, understand r values from -1 to 1, and see how outliers affect correlation
Correlation Explorer
ExplorationExplore Pearson correlation between two variables with interpretation and r² analysis
Regression to the Mean
ExplorationUnderstand why extreme values tend toward average on remeasurement, and why this statistical phenomenon is often mistaken for a causal effect
Survival
8 explorationsCompeting Risks
ExplorationExplore how multiple causes of failure interact through cumulative incidence functions, cause-specific hazards, and overall survival
Cox Proportional Hazards Model
ExplorationExplore the Cox regression model - the workhorse of survival analysis - and understand how covariates affect hazard and survival
Hazard Function Concepts
ExplorationUnderstand hazard rate h(t) as instantaneous risk, its relationship to survival S(t), and cumulative hazard H(t)
The Kaplan-Meier Estimator
ExplorationLearn how to estimate survival probabilities from censored data using the non-parametric Kaplan-Meier method
Log-Rank Test for Survival Curves
ExplorationCompare survival curves between two groups using the log-rank test, understand the test statistic, and interpret p-values
Parametric Survival Models
ExplorationExplore fully specified survival distributions including exponential, Weibull, log-normal, and log-logistic models
Survival Analysis Overview
ExplorationExplore Kaplan-Meier estimation, median survival, and log-rank testing for time-to-event data
Survival Function Basics
ExplorationUnderstand the survival function S(t), cumulative distribution function F(t), and probability density function f(t) in time-to-event analysis
Time Series
30 explorationsAdvanced Topics
10Structural Break Detection
ExplorationDetect when statistical properties change using CUSUM — explore the tradeoff between sensitivity and false alarms.
Cointegration & Long-Run Equilibrium
ExplorationTwo non-stationary series can share a stationary linear combination — the basis of pairs trading and error correction.
Cross-Correlation & Lead-Lag
ExplorationMeasure cross-correlation between two series at different lags to detect lead-lag relationships and coupling strength.
Error Correction Models
ExplorationWhen two series are cointegrated, the ECM describes how each adjusts to restore equilibrium. Explore adjustment speeds, half-lives, and weak exogeneity.
Kalman Filter
ExplorationOptimal state estimation from noisy observations — see how the Kalman gain balances model trust vs data trust.
Fractional Differencing
ExplorationBetween stationary and unit root: fractional d creates long memory with hyperbolic ACF decay, Hurst exponent, and spectral poles.
Spectral Analysis
ExplorationView time series in the frequency domain — how AR and MA processes concentrate energy at different frequencies.
Transfer Function Models
ExplorationHow an input X affects output Y through delay, response shape, and decay. Impulse and step responses for dynamic systems.
Dickey-Fuller Test
ExplorationUnderstand the Dickey-Fuller unit root test: non-standard distributions, critical values, test power, and why normal tables don't apply.
Vector Autoregression (VAR)
ExplorationExplore how multiple time series interact through a VAR(1) model with impulse response functions, Granger causality, and stationarity analysis
AR & MA Models
6Autoregressive Processes
ExplorationExplore how AR(1) processes revert to the mean, with impulse responses, variance growth, and shock half-lives.
AR(2) Process Dynamics
ExplorationExplore oscillatory behavior in AR(2) processes: stability triangle, complex vs real roots, damped oscillations, and characteristic equations.
ARIMA Model Family
ExplorationUnderstand ARIMA(p,d,q): how autoregressive, differencing, and moving average components combine for time series modeling.
ACF & PACF Fingerprints
ExplorationIdentify AR and MA processes from their autocorrelation and partial autocorrelation signatures.
Moving Average Processes
ExplorationUnderstand MA(1) processes — finite memory, ACF cutoff, invertibility, and the maximum autocorrelation bound.
Seasonal ARIMA
ExplorationAdd seasonal components to ARIMA — see how ACF spikes at seasonal lags and how SARIMA captures periodic patterns.
Forecasting
4Bias-Variance Tradeoff
ExplorationExplore the bias-variance decomposition for time series models: how model complexity affects forecast error through bias, variance, and irreducible noise.
Combining Forecasts
ExplorationCombining forecasts often beats any individual one. Explore optimal weights, the diversification benefit, and parallels with portfolio theory.
Prediction Uncertainty
ExplorationWatch forecast intervals widen with horizon — bounded for AR processes, unbounded for random walks.
AIC & BIC Model Selection
ExplorationCompare AIC, BIC, and AICc for model selection: how complexity penalties work, when they disagree, and why BIC is consistent.
Foundations
4Random Walk Theory
ExplorationExplore the foundation of non-stationarity: drift, variance growth, first-passage times, and why random walks mimic trends.
Stationarity & Differencing
ExplorationSee why stationarity matters and how differencing removes trends and unit roots — the 'd' in ARIMA.
Ljung-Box Test
ExplorationTest whether residuals are truly white noise using the Ljung-Box Q statistic and chi-squared critical values.
Wold Decomposition
ExplorationEvery stationary process has an MA(infinity) representation. See how AR(1) psi-weights decay and how many terms capture the variance.
Smoothing & Filtering
4Exponential Smoothing
ExplorationSee how exponential weighting balances responsiveness and stability, with step, ramp, and sine signal responses.
Holt-Winters Triple Smoothing
ExplorationThree smoothing parameters control how fast level, trend, and seasonal components adapt to new data.
Smoothing Filters
ExplorationMoving average filters as low-pass filters: frequency response, cutoff frequency, phase delay, and the tradeoff between smoothing and signal preservation.
Time Series Decomposer
ExplorationDecompose a time series into trend, seasonal, and residual components using additive or multiplicative models with moving average smoothing
Volatility & Regime Models
2GARCH Volatility Models
ExplorationExplore GARCH(1,1) — how volatility clusters, the news impact curve, persistence, and the stationarity condition.
Markov Regime Switching
ExplorationMarkets and economies shift between regimes. Explore transition probabilities, ergodic distributions, expected durations, and regime convergence.
Trigonometry
4 explorationsTrig Identities Explorer
ExplorationVisualize the Pythagorean identity and see how sin² + cos² = 1
Unit Circle Basics
ExplorationA gentle introduction to the unit circle - see how angles create coordinates through sine and cosine
Trigonometry on the Unit Circle
ExplorationExplore how trigonometric functions relate to coordinates on the unit circle, with visual representation of sin, cos, tan, and their relationships
Wave Functions Explorer
ExplorationExplore amplitude, frequency, phase shifts, and vertical shifts in sine and cosine waves