Cauchy distribution
E239287
continuous probability distribution
heavy-tailed distribution
probability distribution
stable distribution
univariate distribution
The Cauchy distribution is a continuous probability distribution with heavy tails and undefined mean and variance, often used as a classic example of pathological behavior in probability theory and statistics.
All labels observed (3)
| Label | Occurrences |
|---|---|
| Cauchy distribution canonical | 3 |
| Breit–Wigner distribution | 1 |
| Lorentz distribution | 1 |
Statements (53)
| Predicate | Object |
|---|---|
| instanceOf |
continuous probability distribution
ⓘ
heavy-tailed distribution ⓘ probability distribution ⓘ stable distribution ⓘ univariate distribution ⓘ |
| belongsToFamily | location–scale family ⓘ |
| correspondsToStudentTWithDegreesOfFreedom | 1 ⓘ |
| definedOn | real line ⓘ |
| hasAllMoments | do not exist ⓘ |
| hasAlternativeName |
Cauchy distribution
ⓘ
surface form:
Breit–Wigner distribution
Cauchy distribution ⓘ
surface form:
Lorentz distribution
|
| hasCharacteristicFunction | φ(t) = exp(i x0 t - γ |t|) ⓘ |
| hasConvolutionProperty | sum of independent Cauchy variables is Cauchy ⓘ |
| hasCumulativeDistributionFunction |
F(x) = 1/π arctan(x) + 1/2
ⓘ
F(x; x0, γ) = 1/π arctan((x - x0)/γ) + 1/2 ⓘ |
| hasEntropy | H = ln(4πγ) ⓘ |
| hasHazardFunction | h(x) = f(x) / (1 - F(x)) for x in ℝ ⓘ |
| hasKurtosis | undefined ⓘ |
| hasLocationParameter |
0
ⓘ
x0 ⓘ |
| hasMean | undefined ⓘ |
| hasMedian | x0 ⓘ |
| hasMedianAbsoluteDeviation | γ ⓘ |
| hasMode | x0 ⓘ |
| hasMomentGeneratingFunction | does not exist ⓘ |
| hasProbabilityDensityFunction |
f(x) = 1 / [π (1 + x^2)]
ⓘ
f(x; x0, γ) = 1 / [πγ (1 + ((x - x0)/γ)^2)] ⓘ |
| hasQuantileFunction | Q(p) = x0 + γ tan[π(p - 1/2)] ⓘ |
| hasScaleParameter |
1
ⓘ
γ ⓘ |
| hasSkewness | 0 ⓘ |
| hasStabilityIndex | 1 ⓘ |
| hasStandardForm | standard Cauchy distribution ⓘ |
| hasSupport | (-∞, ∞) ⓘ |
| hasTailBehavior | f(x) ~ 1/(πγ) · 1/x^2 as |x| → ∞ ⓘ |
| hasVariance | undefined ⓘ |
| isHeavyTailed | true ⓘ |
| isLevyAlphaStable | true ⓘ |
| isSpecialCaseOf |
Lévy alpha-stable distribution
ⓘ
Pearson distribution ⓘ
surface form:
Pearson type VII distribution
Student’s t-distribution ⓘ
surface form:
Student's t-distribution
generalized hyperbolic distribution ⓘ q-Gaussian distribution ⓘ |
| isStable | true ⓘ |
| isSymmetricAbout | x0 ⓘ |
| isUsedAs |
example of distribution with undefined mean
ⓘ
example of distribution with undefined variance ⓘ example of pathological behavior in probability theory ⓘ heavy-tailed prior distribution ⓘ |
| isUsedIn |
Bayesian inference
ⓘ
surface form:
Bayesian statistics
robust statistics ⓘ |
| namedAfter | Augustin-Louis Cauchy ⓘ |
| requiresScaleParameterCondition | γ > 0 ⓘ |
Referenced by (5)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject surface form:
Augustin-Louis Cauchy
this entity surface form:
Lorentz distribution
this entity surface form:
Breit–Wigner distribution