Binary ordinal sums of bivariate copulas #
The first copula occupies [0,a]², the second occupies [a,1]², and the
CDF on the two off-diagonal rectangles is min(u,v). The construction
includes a=0 and a=1. See Nelsen, second edition, §3.2.2.
@[simp]
An endpoint-safe expression for the ordinal-sum CDF.
Equations
- One or more equations did not get rendered due to their size.
Instances For
theorem
ProbabilityTheory.Copula.isClassical_ordinalSumCDF
(C D : Copula 2)
(a : ↑unitInterval)
:
IsClassical fun (u : Fin 2 → ↑unitInterval) => C.ordinalSumCDF D a (u 0) (u 1)
noncomputable def
ProbabilityTheory.Copula.ordinalSum
(C D : Copula 2)
(a : ↑unitInterval)
:
Copula 2
Place C below the split a and D above it, with perfectly ordered block labels.
Equations
- C.ordinalSum D a = ProbabilityTheory.Copula.ofClassical (fun (u : Fin 2 → ↑unitInterval) => C.ordinalSumCDF D a (u 0) (u 1)) ⋯
Instances For
@[simp]
theorem
ProbabilityTheory.Copula.cdf_ordinalSum
(C D : Copula 2)
(a : ↑unitInterval)
(u : Fin 2 → ↑unitInterval)
:
@[simp]
@[simp]
theorem
ProbabilityTheory.Copula.cdf_ordinalSum_lower
(C D : Copula 2)
(a u v : ↑unitInterval)
(hu : u ≤ a)
(hv : v ≤ a)
:
theorem
ProbabilityTheory.Copula.cdf_ordinalSum_upper
(C D : Copula 2)
(a u v : ↑unitInterval)
(hu : a ≤ u)
(hv : a ≤ v)
:
(C.ordinalSum D a).cdf ![u, v] = ↑a + (1 - ↑a) * D.cdf ![OrdinalSum.upperCoord a u, OrdinalSum.upperCoord a v]
theorem
ProbabilityTheory.Copula.cdf_ordinalSum_lower_upper
(C D : Copula 2)
(a u v : ↑unitInterval)
(hu : u ≤ a)
(hv : a ≤ v)
:
theorem
ProbabilityTheory.Copula.cdf_ordinalSum_upper_lower
(C D : Copula 2)
(a u v : ↑unitInterval)
(hu : a ≤ u)
(hv : v ≤ a)
:
@[simp]
theorem
ProbabilityTheory.Copula.cdf_ordinalSum_lowerEmbed
(C D : Copula 2)
(a u v : ↑unitInterval)
(ha : 0 < a)
:
theorem
ProbabilityTheory.Copula.cdf_ordinalSum_upperEmbed
(C D : Copula 2)
(a u v : ↑unitInterval)
(ha : a < 1)
:
(C.ordinalSum D a).cdf ![OrdinalSum.upperEmbed a u, OrdinalSum.upperEmbed a v] = ↑a + (1 - ↑a) * D.cdf ![u, v]