Health
Interpret Jamar / Camry / EH101 grip readings against age/sex population norms (Massy-Westropp 2011: z-score, percentile, % of norm), sarcopenia weakness cutoffs (EWGSOP2, AWGS, Fried), the 10% asymmetry rule; compute rate of force development from force-time curves (0–50…0–250 ms windows, peak RFD, impulse, time-to-peak per Maffiuletti 2016); and repeated-trial fatigue index.
grip-strength-dynamometer-and-rate-of-force-development-tutorGeography
Encode lat/lng into Uber H3 hexagons (res 0-15) and Google S2 Hilbert cells (level 1-30) with index, id, token, quadkey, areas, k-ring neighbors, compaction, parent ladders and round-trip drift.
h3-and-s2-hexagonal-cell-index-encoder-and-neighbor-bridgeHealth
Run SIR / SEIR / SEIR+V / SEIR+H ODEs with RK4: R0, herd-immunity threshold, analytic peak and final-size equations, growth-rate conversion, WAIFW next-generation-matrix R0, incidence fitting and intervention simulation.
sir-seir-compartmental-epidemic-r0-and-intervention-modeling-coachData Visualization
Upload or paste a CSV and chart it instantly: histograms with Sturges / Freedman-Diaconis / Scott binning, scatter plots with Pearson r and a least-squares fit, and Tukey box plots — every chart downloadable as PNG and SVG.
csv-histogram-scatter-box-plot-chart-studioAstronomy
Solve Galilean satellite positions with Meeus/Lieske E5 series, chart the Laplace-resonance libration, scan mutual events and eclipses, model a Europa Clipper-style flyby with patched-conic Δv, and solve Jupiter Cassini states from J2 oblateness precession.
jovian-galilean-moons-europa-flyby-cassini-state-and-resonance-solverScience & Education
Run the three workhorse normality tests (Shapiro-Wilk AS R94, Anderson-Darling, Lilliefors) with a Q-Q plot and a Monte-Carlo power comparison.
shapiro-wilk-anderson-darling-lilliefors-normality-tutorNetwork
Parse RFC 8288 Link headers with the spec appendix-B algorithm, resolve relative URI-references against a base URL, classify rel types against the IANA registry, validate preload/prefetch hints, and simulate how a rel="next" pagination crawler walks your responses — including cycle detection.
http-link-header-rfc8288-parser-and-pagination-crawler-previewSports
Plan a HYROX race end to end: per-lap 1 km run splits under an even, negative-split or fade strategy, auto-distributed station targets for your finish time, the 8 Roxzone transition budget, and your division’s official sled push/pull weights with the plate stack to load.
hyrox-race-station-split-and-sled-loading-plannerScience & Education
k = A·e^(−Ea/RT) solved for k, A, or Ea (two-point form), with Ea in kJ/mol and kcal/mol.
arrhenius-equation-calculatorScience & Education
ΔT_b = K_b·m·i from a solvent preset table with van't Hoff factor support and custom solvents.
boiling-point-elevationDevelopment
Test .NET/C# regular expressions online with named groups ((?<name>…)), IgnoreCase/Multiline/Singleline options, match highlighting, capture-group tables, a ready-to-paste C# snippet and an IgnorePatternWhitespace preview.
csharp-regex-testerScience & Education
t½ = a₀/(2k), ln 2/k or 1/(k·a₀) for zero-, first- and second-order reactions, with timelines and depletion time.
half-life-reaction-order