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Cauchy Distribution

A heavy-tailed distribution where mean and variance are undefined. Educational for understanding pathological distributions.

Probability Density FunctionPDF = f(x)
Cumulative Distribution FunctionCDF = F(x)
Probability in an Interval
Compute the probability that X falls between two values. For continuous distributions, this is the shaded area under the PDF (≤ vs < doesn't matter).
P(a ≤ X ≤ b)
Quantiles (Inverse CDF)
Pick a probability p and read the corresponding quantile xₚ where F(xₚ) = p.
Quantile xₚ (where F(xₚ) = p)
In Cauchy Distribution, selected probability p: 0.9500 (95.00%)

Parameters

Adjust the parameters and (optionally) add up to 3 curves to compare different settings side‑by‑side.

0 curves shown

Estimating parameters from data

If you’re fitting this distribution to observed data, these are common plug‑in estimates you can start with.

Location (x₀)

Use the sample median (not the mean, which is undefined).

Scale (γ)

Estimate from the interquartile range: γ = IQR/2.