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256 tools in this collection. Choose a task below or search the complete FeuTex toolkit.

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Statistics

2D Mahalanobis Distance

Measure a point displacement while accounting for correlated variable scales.

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Math

2D Polar Rotation from a Matrix

Extract the closest proper rotation from an orientation-preserving 2×2 transform.

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Math

2×2 Cholesky Factorization

Factor a symmetric positive-definite matrix into a lower triangular matrix and its transpose.

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Statistics

2×2 Independence Statistic

Calculate Pearson’s independence statistic and signed association for a two-by-two count table.

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Math

2×2 Matrix Inverse

Invert a nonsingular two-by-two matrix and inspect its determinant.

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Math

2×2 Singular Values and Conditioning

Find both singular values and the spectral condition number of a nonsingular two-by-two matrix.

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Statistics

Adjusted R-Squared and Residual Scale

Adjust regression R-squared for predictor count and calculate residual scale and degrees of freedom.

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Geometry

Affine Point Transformation

Apply a two-dimensional affine map and inspect its area scale and orientation.

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Math

Aitken Sequence Acceleration

Accelerate a linearly convergent sequence from three successive iterates.

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Geometry

Annulus Area Calculator

Calculate annulus area with labeled inputs, explicit units and the formula A = π(R² − r²).

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Statistics

AR(1) Conditional Forecast

Project a stationary autoregressive series and its innovation variance over a horizon.

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Statistics

AR(1) Effective Sample Size

Approximate the information loss in a mean estimate from positive first-order serial correlation.

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Geometry

Arc Length Calculator

Calculate arc length with labeled inputs, explicit units and the formula s = πrθ / 180.

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Probability

Arcsine Bounded Interval Probability

Calculate probability between two points under the U-shaped arcsine distribution.

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Math

Arithmetic Sequence Sum Calculator

Calculate arithmetic sequence sum with labeled inputs, explicit units and the formula Sₙ = n[2a₁+(n−1)d]/2.

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Math

Arithmetic Sequence Term Calculator

Calculate arithmetic sequence term with labeled inputs, explicit units and the formula aₙ = a₁+(n−1)d.

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Math

Balanced Parenthesis Structure Count

Count valid balanced-parenthesis sequences and equivalent ordered binary tree shapes.

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Geometry

Barycentric Point Location

Express a point as three triangle weights to inspect its location relative to the triangle.

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Math

Bayes Probability Calculator

Calculate bayes probability with labeled inputs, explicit units and the formula P(A|B)=P(B|A)P(A)/[P(B|A)P(A)+P(B|¬A)(1−P(A))].

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Statistics

Bernoulli KL Divergence

Measure the information penalty of using one binary event probability in place of another.

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Probability

Beta Distribution Moments

Inspect a beta distribution’s mean, variance and skewness on the unit interval.

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Math

Bilinear Grid Cell Interpolation

Interpolate a rectangular data cell from four corner values.

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Statistics

Binary Classification Scorecard

Evaluate precision, recall, specificity, F1 and Matthews correlation from a binary confusion matrix.

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Probability

Binary Entropy Profile

Calculate uncertainty, perplexity and success information for a Bernoulli probability.

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Statistics

Binary Mutual Information from Counts

Measure dependence between two binary variables using a positive 2×2 count table.

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Statistics

Binary Rater Agreement

Compare observed agreement with chance agreement and calculate Cohen’s kappa for two binary raters.

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Math

Binomial Exact Probability Calculator

Calculate binomial exact probability with labeled inputs, explicit units and the formula P(X=k)=C(n,k)pᵏ(1−p)ⁿ⁻ᵏ.

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Probability

Birthday Collision Estimate

Estimate collision probability and expected matching pairs for independent draws from equal-probability categories.

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Math

Bisection Iteration Budget

Find iterations needed to reduce a root bracket below a target width.

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Statistics

Bland–Altman Agreement Limits

Calculate mean bias and normal-theory limits of agreement from paired-difference summaries.

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Math

Boole Five-Point Integration

Integrate a smooth function using five equally spaced samples and Boole weights.

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Statistics

Bowley Quartile Skewness

Assess robust asymmetry using the lower quartile, median, and upper quartile.

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Probability

Burr XII Tail Distribution

Explore two-shape tail probabilities for positive continuous data.

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Probability

Cantelli One-Sided Tail Bound

Bound a one-sided deviation from the mean using variance alone.

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Geometry

Catenary Sag and Arc Length

Estimate the sag, total arc length and end slope of a symmetric mathematical catenary.

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Probability

Cauchy Distribution Profile

Evaluate Cauchy cumulative probability, density and interquartile range without undefined moments.

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Math

Centered Derivative Stencil

Estimate first and second derivatives from three equally spaced function measurements.

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Probability

Chebyshev Coverage Guarantee

Bound the fraction outside a selected distance from the mean using only finite variance.

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Geometry

Circle Area Calculator

Calculate circle area with labeled inputs, explicit units and the formula A = πr².

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Geometry

Circle Chord Length Calculator

Calculate circle chord length with labeled inputs, explicit units and the formula c = 2r sin(θ/2).

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Geometry

Circle Circumference Calculator

Calculate circle circumference with labeled inputs, explicit units and the formula C = 2πr.

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Geometry

Circle Overlap Lens

Calculate the shared lens area and common chord where two circles partially overlap.

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Geometry

Circle Sector Area Calculator

Calculate circle sector area with labeled inputs, explicit units and the formula A = πr²θ / 360.

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Geometry

Circle through Three Points

Locate the center and radius of the unique circle passing through three noncollinear points.

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Geometry

Circular Segment Profile

Find a circular segment’s area, chord width and central angle from its radius and height.

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Geometry

Closed Cone Surface Area Calculator

Calculate closed cone surface area with labeled inputs, explicit units and the formula A = πr[r + √(r²+h²)].

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Geometry

Closed Cylinder Surface Area Calculator

Calculate closed cylinder surface area with labeled inputs, explicit units and the formula A = 2πr(r+h).

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Statistics

Cluster Sampling Design Effect

Estimate sample inflation from average cluster size and within-cluster correlation.

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Statistics

Cochran Q from Study Summaries

Calculate meta-analysis heterogeneity metrics from Q, study count, and inverse-variance weight sums.

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Math

Coefficient of Variation Calculator

Calculate coefficient of variation with labeled inputs, explicit units and the formula CV = 100σ/μ.

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Geometry

Common External Tangent of Two Circles

Find the straight external tangent length between circles for a geometric construction.

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Math

Complex Exponential Evaluation

Evaluate exp(a+bi) as Cartesian real and imaginary parts.

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Math

Complex Magnitude, Phase and Principal Root

Find magnitude, phase and the principal square root of a complex number.

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Math

Complex Product and Quotient

Multiply and divide two complex numbers while keeping real and imaginary components separate.

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Math

Composite Simpson Panel Budget

Estimate an even panel count sufficient for a supplied fourth-derivative bound.

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Math

Composite Trapezoidal Error Bound

Bound integration error using a second-derivative bound and panel count.

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Geometry

Cone Frustum Flat Pattern

Calculate the annular-sector radii and sweep for unrolling a cone frustum.

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Geometry

Cone Frustum Volume Calculator

Calculate cone frustum volume with labeled inputs, explicit units and the formula V = πh(R²+Rr+r²)/3.

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Geometry

Cone Solid Angle and Sphere Fraction

Calculate a cone aperture’s solid angle and the fraction of a sphere it covers.

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Geometry

Cone Volume Calculator

Calculate cone volume with labeled inputs, explicit units and the formula V = πr²h/3.

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Statistics

Cook Distance for One Observation

Estimate regression influence from residual, leverage, parameter count, and residual mean square.

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Statistics

Correlated Measurement Uncertainty

Propagate correlated standard uncertainties through a sum, difference and product.

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Statistics

Correlation Correction for Attenuation

Estimate a latent correlation under classical independent measurement-error assumptions.

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Statistics

Correlation Fisher Interval

Construct an approximate Fisher-transformed confidence interval for a Pearson correlation.

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Probability

Coupon Collection Expectation

Calculate the expected draw count and variance needed to collect every uniformly distributed coupon type.

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Statistics

Cronbach Alpha from Variance Summaries

Estimate internal consistency from item count, summed item variances, and total-score variance.

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Math

Cubic Hermite Endpoint Interpolation

Interpolate between endpoint values while preserving specified endpoint slopes.

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Math

Cubic Polynomial Evaluation

Evaluate a cubic polynomial, its first two derivatives and its signed integral from zero.

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Geometry

Cuboid Space Diagonal Calculator

Calculate cuboid space diagonal with labeled inputs, explicit units and the formula d = √(l²+w²+h²).

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Geometry

Cuboid Surface Area Calculator

Calculate cuboid surface area with labeled inputs, explicit units and the formula A = 2(lw + wh + lh).

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Geometry

Cuboid Volume Calculator

Calculate cuboid volume with labeled inputs, explicit units and the formula V = length × width × height.

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Geometry

Cyclic Quadrilateral from Four Sides

Calculate area and diagonal lengths of a convex cyclic quadrilateral.

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Geometry

Cycloid Point and Tangent

Locate a point on a rolling-circle cycloid and evaluate its parametric tangent.

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Geometry

Cylinder Volume Calculator

Calculate cylinder volume with labeled inputs, explicit units and the formula V = πr²h.

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Statistics

Descriptive Statistics

Summarize a numeric sample with count, mean, median, sample standard deviation and range.

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Math

Distance Between Two Points Calculator

Calculate distance between two points with labeled inputs, explicit units and the formula d = √[(x₂−x₁)²+(y₂−y₁)²].

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Geometry

Ellipse Area Calculator

Calculate ellipse area with labeled inputs, explicit units and the formula A = πab.

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Geometry

Ellipse Foci and Eccentricity

Find an ellipse’s focal offset, eccentricity and latus rectum from its major and minor semi-axes.

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Geometry

Ellipse Local Radius of Curvature

Measure curvature and osculating radius at a location on an elliptical curve.

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Geometry

Ellipse Sector Area by Parameter

Measure an ellipse sector swept between two parametric angles.

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Geometry

Ellipse Tangent at Parametric Angle

Locate an ellipse point and its tangent line without a vertical-slope singularity.

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Statistics

Empirical CDF Uniform Error Band

Calculate the Dvoretzky–Kiefer–Wolfowitz simultaneous CDF error bound.

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Statistics

Expected Binary Brier Score

Measure expected squared-probability error from a true binary event rate and a constant forecast.

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Probability

Exponential Lifetime Profile

Calculate survival probability, cumulative probability and typical waiting times under constant hazard.

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Math

Exponential Relaxation Rate from Two Observations

Infer a first-order relaxation constant from a starting offset and a later offset from equilibrium.

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Statistics

Exponential Smoothing Forecast Update

Update a simple level forecast from one new observation and a smoothing weight.

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Math

Exponential Trend Doubling or Halving Time

Translate a continuous fitted log-growth coefficient into a multiplicative trend timescale.

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Math

Fibonacci Index Values

Calculate Fibonacci and Lucas numbers at a bounded nonnegative integer index.

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Math

Finite Arithmetic–Geometric Sum

Sum a sequence whose terms combine an arithmetic factor with a geometric weight.

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Statistics

Finite Population Sample Adjustment

Adjust an infinite-population sample-size requirement for sampling without replacement.

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Math

Five-Point First Derivative

Estimate a first derivative with a fourth-order centered stencil.

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Math

Fixed-Point Contraction Error Bound

Bound remaining iteration error from a contraction factor and successive iterate difference.

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Math

Four-Sample Fourier Transform

Transform four equally spaced real samples into their discrete Fourier frequency components.

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Math

Fraction Arithmetic

Add, subtract, multiply or divide two rational fractions and reduce the result exactly.

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Probability

Frechet Maximum Tail Model

Evaluate heavy-tailed maxima using a Frechet shape and scale.

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Statistics

Freedman–Diaconis Histogram Width

Plan histogram bin width and count from sample size, range, and interquartile range.

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Statistics

Frequency Table Builder

Count exact categorical values and show their percentage share.

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Probability

Gambler Ruin Hitting Probability

Find the probability that a bounded random walk reaches its upper boundary before zero.

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Probability

Gamma Distribution Moments

Inspect a gamma distribution’s mean, variance, skewness and excess kurtosis using shape and scale.

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Statistics

Gaussian Bhattacharyya Overlap

Calculate a normal-model overlap coefficient based on means and variances.

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Statistics

Gaussian KL Divergence

Quantify directed divergence between two univariate normal distributions.

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Statistics

Gaussian Wasserstein Distance

Measure the transport distance between two one-dimensional Gaussian models.

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Probability

Generalized Pareto Threshold Exceedance

Estimate excess-tail probability and a return-level quantile above a selected threshold.

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Math

Geometric Sequence Sum Calculator

Calculate geometric sequence sum with labeled inputs, explicit units and the formula Sₙ = a₁(1−rⁿ)/(1−r), or na₁ when r=1.

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Math

Geometric Sequence Term Calculator

Calculate geometric sequence term with labeled inputs, explicit units and the formula aₙ = a₁rⁿ⁻¹.

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Probability

Geometric Waiting-Time Probability

Calculate exact and cumulative waiting probabilities before the first successful trial.

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Math

Gompertz Growth Trajectory

Evaluate a Gompertz growth curve, its instantaneous growth and its inflection time.

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Geometry

Great-Circle Distance

Measure the shortest spherical surface route and straight chord between two latitude-longitude positions.

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Probability

Gumbel Maximum Distribution

Evaluate a Gumbel maximum distribution’s cumulative probability, median and variance.

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Math

Halley Root-Finding Step

Calculate a cubic-convergence root update using a function and its first two derivatives.

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Geometry

Helix Path Profile

Measure a circular helix’s length, rise, curvature and torsion from radius, pitch and turns.

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Statistics

Histogram Bin Counter

Count values into equal-width bins and export the bin boundaries and frequencies.

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Probability

Hoeffding Mean Deviation Bound

Bound sample-mean deviations for independent observations with known finite limits.

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Statistics

Holt Linear Trend Forecast Step

Update a level and trend then project a selected number of steps forward.

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Geometry

Hyperbola Foci and Asymptotes

Find focal distance, eccentricity and asymptote slope for a horizontal hyperbola.

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Math

Implicit Curve Local Geometry

Compute slope and curvature of F(x,y)=0 from first and second partial derivatives.

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Math

Independent Event Union Probability Calculator

Calculate independent event union probability with labeled inputs, explicit units and the formula P(A or B) = a+b−ab.

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Geometry

Internal Angle Bisector Length

Find the internal angle bisector and how it divides the opposite side.

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Statistics

Inverse-Variance Two-Study Pooling

Combine two independent effect estimates using inverse-variance weighting.

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Statistics

Jarque–Bera Normality Statistic

Calculate an asymptotic normality statistic from sample size, skewness, and raw kurtosis.

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Probability

Kumaraswamy Bounded Probability

Evaluate a flexible continuous probability model for a quantity bounded between zero and one.

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Probability

Laplace Distribution Profile

Evaluate Laplace cumulative probability, density and variance from location and scale.

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Geometry

Lattice Polygon Area from Point Counts

Find the area of a simple lattice polygon from its interior and boundary lattice points.

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Statistics

Likelihood Information Criteria

Calculate AIC, small-sample AICc and BIC from a fitted model’s likelihood and parameter count.

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Statistics

Lin Concordance Correlation

Measure agreement of two continuous measurements using means, spreads, and Pearson correlation.

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Geometry

Line and Plane Intersection

Find the parameter and coordinates where a 3D parametric line crosses a plane.

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Math

Line Slope Calculator

Calculate line slope with labeled inputs, explicit units and the formula m = (y₂−y₁)/(x₂−x₁).

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Math

Linear Interpolation Calculator

Calculate linear interpolation with labeled inputs, explicit units and the formula y = y₁ + (x−x₁)(y₂−y₁)/(x₂−x₁).

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Statistics

Linear Regression

Fit y = intercept + slope × x to paired observations and report R².

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Math

Linear System Solver

Solve a square system of linear equations with partial-pivot Gaussian elimination.

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Probability

Log-Logistic Lifetime Model

Calculate a log-logistic survival curve and instantaneous hazard at a chosen age.

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Math

Logarithm in Any Base Calculator

Calculate logarithm in any base with labeled inputs, explicit units and the formula logᵦ(x) = ln(x)/ln(b).

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Probability

Logistic Distribution Profile

Evaluate logistic cumulative probability, density and variance from location and scale.

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Math

Logistic Growth Trajectory

Evaluate a logistic growth model at a chosen time with an explicit carrying capacity.

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Math

Logistic Map Dynamics

Inspect the next state, local derivative and nonzero fixed point of the logistic map.

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Probability

Lognormal Moment Profile

Find a lognormal model’s median, mean, variance and mode from natural-log parameters.

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Probability

Markov Nonnegative Tail Bound

Bound exceedance probability for a nonnegative random quantity from its expected value.

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Statistics

McNemar Paired Discordance

Inspect corrected and uncorrected McNemar statistics from paired discordant outcomes.

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Statistics

Mean Confidence Interval from Summary

Construct a mean confidence interval from summary statistics and a supplied t critical value.

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Statistics

Mean Precision Sample Size

Estimate the sample count needed for a target mean-estimation precision with known variability.

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Statistics

Merge Two Sample Summaries

Combine two disjoint sample summaries into one count, mean and sample variance.

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Statistics

Moving Average Series

Smooth a numeric time series using a trailing simple moving average of your chosen window.

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Statistics

Multiple-Testing Error Budget

Allocate a family-wise error budget and adjust one p-value using Bonferroni’s method.

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Geometry

Nearest Point on a Line Segment

Find the nearest point on a finite line segment, including endpoint cases.

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Statistics

Nested Regression F Comparison

Compare reduced and full least-squares models using residual sums of squares.

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Math

Newton Root-Finding Step

Perform one Newton root-finding iteration using a supplied function value and derivative.

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Probability

No-Fixed-Point Assignment Count

Count assignments with no item in its original position and calculate their random-permutation probability.

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Geometry

Oblique Cylinder Geometry

Compute perpendicular height and volume from an oblique cylinder axis.

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Math

Observed Iterative Convergence Order

Estimate convergence order from three successive positive errors against a known solution.

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Statistics

One-Way ANOVA Summary

Build one-way ANOVA statistics and effect size from between-group and within-group sums of squares.

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Statistics

One-Way Intraclass Correlation

Estimate single-measure intraclass correlation from balanced one-way ANOVA mean squares.

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Math

Ordered and Unordered Selections

Count selections without replacement with and without regard to ordering.

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Statistics

Paired Difference Test Statistic

Calculate a paired-sample test statistic from the mean and standard deviation of paired differences.

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Geometry

Pappus Solid of Revolution

Compute swept volume and surface using a region area, curve length, and centroid distances.

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Geometry

Parabola Focus and Directrix

Locate the focus and directrix of a vertical parabola and calculate its focal chord width.

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Geometry

Parallelogram Area Calculator

Calculate parallelogram area with labeled inputs, explicit units and the formula A = bh.

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Probability

Pareto Tail Profile

Calculate Pareto exceedance probability and finite moments for a heavy-tailed model.

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Statistics

Partial Correlation Controlling One Variable

Remove one control variable from the relationship between two measured variables.

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Geometry

Plane Angle and Intersection Direction

Find the acute angle between planes and a direction vector for their intersection line.

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Geometry

Platonic Solid Comparison

Compare the volumes of four regular Platonic solids sharing one edge length.

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Geometry

Point Inversion in a Circle

Map a planar point through a geometric inversion circle while preserving its radial direction.

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Geometry

Point Projection onto a Line

Find the perpendicular distance and closest point from a coordinate to an infinite line.

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Geometry

Point Projection onto a Plane

Project a three-dimensional point onto a plane and measure its perpendicular distance.

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Geometry

Point Rotation about a Center

Rotate a planar point counterclockwise around a chosen center.

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Probability

Poisson Event Window

Estimate the probabilities of no events, one event or multiple events in a constant-rate window.

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Math

Polar Curve Curvature from Derivatives

Calculate local curvature of a polar curve from radius and angular derivatives.

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Statistics

Pooled Standardized Mean Difference

Compare group means in pooled-standard-deviation units using two independent sample summaries.

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Math

Power-Law Interpolation

Interpolate positive measurements along a straight line on log-log axes.

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Math

Prime Factorization

Find the prime factors of an integer and show exponent notation.

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Statistics

Process Capability Indices

Compare a stable process with specification limits using Cp, Cpk and one-sided capability indices.

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Geometry

Pyramid Volume Calculator

Calculate pyramid volume with labeled inputs, explicit units and the formula V = base area × height / 3.

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Geometry

Quadratic Bézier Point and Tangent

Evaluate a point and tangent on a quadratic Bézier curve from three control points.

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Math

Quadratic Discriminant Calculator

Calculate quadratic discriminant with labeled inputs, explicit units and the formula D = b²−4ac.

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Math

Quadratic Real Root Solver

Find both real roots and the vertex of a quadratic polynomial from its coefficients.

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Math

Quadratic Vertex and Axis

Find the turning point and completed-square constant of a quadratic.

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Geometry

Quadrilateral Coordinate Survey

Calculate signed area and perimeter from four consecutive boundary coordinates.

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Probability

Random Bin Occupancy

Estimate occupied, empty and singleton bins after independent uniform assignments.

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Math

Rank-One Determinant Update

Update a known matrix determinant from the scalar rank-one correction vᵀA⁻¹u.

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Probability

Rayleigh Distribution Profile

Evaluate Rayleigh density, cumulative probability, mean and variance for a nonnegative magnitude.

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Geometry

Rectangle Area Calculator

Calculate rectangle area with labeled inputs, explicit units and the formula A = width × height.

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Geometry

Rectangle Diagonal Calculator

Calculate rectangle diagonal with labeled inputs, explicit units and the formula d = √(width² + height²).

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Geometry

Rectangle Perimeter Calculator

Calculate rectangle perimeter with labeled inputs, explicit units and the formula P = 2(width + height).

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Geometry

Reflect a Point across a Plane

Mirror a three-dimensional point across a plane given by its coefficients.

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Geometry

Regular Polygon Area Calculator

Calculate regular polygon area with labeled inputs, explicit units and the formula A = ns² / [4 tan(π/n)].

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Geometry

Regular Polygon Interior Angle Calculator

Calculate regular polygon interior angle with labeled inputs, explicit units and the formula θ = 180(n−2)/n.

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Geometry

Regular Star Polygon Path Length

Measure edge length and total traversal length for a regular star polygon step.

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Math

Reverse Percentage Calculator

Calculate reverse percentage with labeled inputs, explicit units and the formula original = final / (1 + change/100).

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Geometry

Rhombus Area from Diagonals Calculator

Calculate rhombus area from diagonals with labeled inputs, explicit units and the formula A = d₁d₂/2.

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Math

Richardson Extrapolation

Extrapolate two numerical estimates to zero step size using a known leading error order.

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Geometry

Right Triangle Missing Leg Calculator

Calculate right triangle missing leg with labeled inputs, explicit units and the formula b = √(c² − a²).

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Geometry

Rounded Rectangle Outline and Area

Calculate area and perimeter for a rectangle with four equal circular corner fillets.

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Math

Runge–Kutta Four-Stage Step

Combine four correctly evaluated Runge–Kutta stage slopes into one fourth-order solution step.

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Probability

Sampling Without Replacement

Estimate the mean, variance and feasible success range when sampling without replacement.

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Math

Scientific Expression Calculator

Evaluate arithmetic, powers, roots, logarithms and trigonometry with explicit degree or radian mode.

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Math

Secant Root-Finding Step

Calculate the next secant-method root estimate using two positions and function values.

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Statistics

Set Overlap from Cardinalities

Compare two finite sets using their sizes and shared-element count.

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Geometry

Shortest Distance Between Skew Lines

Find separation between two nonparallel 3D lines using their origins and direction vectors.

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Statistics

Simple Regression Prediction Interval

Calculate a prediction interval for one new response using regression summary quantities.

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Math

Simpson Integration Panel

Integrate three equally spaced measurements using Simpson’s rule and compare a trapezoid estimate.

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Math

Simpson Three-Eighths Panel

Integrate one cubic interpolating panel from four equally spaced function samples.

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Statistics

Spearman–Brown Test Length Projection

Project reliability after changing the length of a parallel-item test.

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Geometry

Sphere Cut by a Plane

Find a circular section area and radius for a plane at a given offset from a sphere center.

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Geometry

Sphere Intersection Volume

Measure the shared volume and intersection-circle radius of two partially overlapping spheres.

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Geometry

Sphere Surface Area Calculator

Calculate sphere surface area with labeled inputs, explicit units and the formula A = 4πr².

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Geometry

Sphere Volume Calculator

Calculate sphere volume with labeled inputs, explicit units and the formula V = 4πr³/3.

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Geometry

Spherical Cap Profile

Measure a sphere cap’s volume, curved surface and base radius from cap height.

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Geometry

Spherical Coordinate Position

Convert a spherical position to Cartesian coordinates with explicit polar-angle conventions.

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Geometry

Spherical Triangle Excess and Area

Calculate spherical excess and surface area from three angles on a chosen sphere.

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Geometry

Spherical Zone Surface and Volume

Find the sphere surface band and solid volume between two parallel cut planes.

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Geometry

Stadium Shape Area and Boundary

Calculate a capsule-shaped outline formed by a rectangle and two semicircular ends.

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Math

Standard Error of the Mean Calculator

Calculate standard error of the mean with labeled inputs, explicit units and the formula SE = s/√n.

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Statistics

Standardized Regression Coefficient

Convert a fitted unstandardized slope and its error to standardized units.

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Geometry

Superellipse Boundary Point

Locate a point on a rounded rectangle or diamond-like superellipse using its exponent.

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Math

Symmetric 2×2 Matrix Spectrum

Calculate the two real eigenvalues and principal-axis angle of a symmetric two-by-two matrix.

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Geometry

Tetrahedron Volume from Edge Vectors

Compute the volume and orientation of a tetrahedron from its three shared-origin edge vectors.

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Statistics

Three-Class Split Impurity

Evaluate Gini impurity and entropy of a node containing three class counts.

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Math

Three-Level Continued Fraction

Evaluate a short continued fraction and its exact numerator-denominator recurrence.

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Math

Three-Node Polynomial Interpolation

Interpolate a quadratic through three data points and evaluate its value and derivative.

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Geometry

Torus Volume Calculator

Calculate torus volume with labeled inputs, explicit units and the formula V = 2π²Rr².

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Geometry

Trapezoid Area Calculator

Calculate trapezoid area with labeled inputs, explicit units and the formula A = (a+b)h/2.

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Probability

Trials until Multiple Successes

Estimate trial count and variability required to reach multiple independent successes.

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Geometry

Triangle Area Calculator

Calculate triangle area with labeled inputs, explicit units and the formula A = base × perpendicular height / 2.

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Geometry

Triangle Area from Three Sides Calculator

Calculate triangle area from three sides with labeled inputs, explicit units and the formula A = √[s(s−a)(s−b)(s−c)], s = (a+b+c)/2.

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Geometry

Triangle Centroid Coordinates

Locate a triangle’s centroid and measure its first median from three vertex coordinates.

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Geometry

Triangle from Two Sides and Included Angle

Solve a triangle’s remaining side, angles and area from two sides and their included angle.

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Geometry

Triangle Incircle and Circumcircle

Find the inscribed and circumscribed circle radii of a triangle from its three side lengths.

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Geometry

Triangle Median Lengths

Find all three medians to plan centroid bracing or check a triangle construction.

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Geometry

Triangle Orthocenter from Coordinates

Locate the intersection of triangle altitudes from three measured vertices.

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Probability

Triangular Distribution Profile

Evaluate cumulative probability and moments for a minimum-mode-maximum triangular distribution.

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Geometry

Triaxial Ellipsoid Profile

Calculate the volume and three central cross-sections of an ellipsoid with unequal semi-axes.

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Statistics

Tukey Inner and Outer Fences

Calculate boxplot screening fences from quartiles without deleting observations.

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Statistics

Two-Bin Population Stability Index

Compare the share of observations in two fixed bins between reference and current populations.

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Statistics

Two-Group Event Association

Compare two groups using risk ratio, risk difference, odds ratio and log-odds uncertainty.

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Probability

Two-Group Exponential Survival

Model survival when a population contains two latent groups with different constant rates.

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Math

Two-Group Weighted Mean Calculator

Calculate two-group weighted mean with labeled inputs, explicit units and the formula mean = (a×w₁+b×w₂)/(w₁+w₂).

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Geometry

Two-Line Intersection

Find the unique intersection of two planar lines expressed in coefficient form.

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Math

Two-Node Gauss Integration Panel

Combine function values at the two mapped Gauss–Legendre nodes of an interval.

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Statistics

Two-Proportion Z Statistic

Calculate the pooled large-sample z statistic comparing two independent event proportions.

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Statistics

Two-Sample Variance Ratio

Compute an F variance-ratio statistic and degrees of freedom from two samples.

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Probability

Two-State Markov Equilibrium

Calculate long-run state proportions and persistence for a two-state transition process.

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Math

Two-Value RMS Calculator

Calculate two-value rms with labeled inputs, explicit units and the formula RMS = √[(a²+b²)/2].

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Math

Two-Variable Quadratic Stationary Point

Find the stationary point and minimum value of a positive-definite quadratic form.

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Math

Two-Vector Gram–Schmidt in 2D

Create an orthonormal 2D basis from two independent input vectors.

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Math

Uneven Three-Point Derivative

Estimate the derivative at a center sample when left and right spacing differ.

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Probability

Uniform Distribution Interval

Find interval probability, mean and variance for a bounded uniform distribution.

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Statistics

Variance Inflation and Tolerance

Measure coefficient variance inflation from the auxiliary regression R-squared.

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Geometry

Vector Angle and Projection

Measure the angle between two planar vectors and project the first onto the second.

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Geometry

Vector Cross Product

Calculate a three-dimensional cross product and the parallelogram area spanned by two vectors.

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Probability

Weibull Lifetime Profile

Evaluate Weibull survival, failure probability, instantaneous hazard and median lifetime.

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Statistics

Weight Effective Sample Size

Estimate weight-based effective sample size and efficiency from sums of weights and squared weights.

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Statistics

Welch Two-Sample Test Statistic

Calculate Welch’s two-sample statistic and approximate degrees of freedom from group summaries.

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Statistics

Welch–Satterthwaite Combined Degrees of Freedom

Calculate effective degrees of freedom for a sum of independent estimated variance components.

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Statistics

Wilson Proportion Interval

Calculate a Wilson score confidence interval for a proportion from successes and trials.

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Math

Z Score Calculator

Calculate z score with labeled inputs, explicit units and the formula z = (x−μ)/σ.

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Statistics

Zero-Event Upper Risk Bound

Estimate a one-sided event-probability upper bound after observing no events.

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Probability

Zero-Inflated Poisson Count Model

Estimate zero frequency and overdispersion when a count process has structural zeros.

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