Commit 2024-03-17 17:51 8a25f82b
View on Github →feat(Probability/Kernel): build a kernel from a kernel CDF (#11209)
Let κ : kernel α (β × ℝ)
and ν : kernel α β
be two finite kernels. A function f : α × β → StieltjesFunction
is called a conditional kernel CDF of κ
with respect to ν
if it is measurable, tends to to 0 at -∞ and to 1 at +∞ for all p : α × β
, if fun b ↦ f (a, b) x
is (ν a)
-integrable for all a : α
and x : ℝ
and for all measurable sets s : Set β
, ∫ b in s, f (a, b) x ∂(ν a) = (κ a (s ×ˢ Iic x)).toReal
.
From such a function with property hf : IsCondKernelCDF f κ ν
, we build a kernel (α × β) ℝ
denoted by hf.toKernel f
such that κ = ν ⊗ₖ hf.toKernel f
.
The new file has substantial overlap with the contents of Probability.Kernel.Disintegration
and Probability.Kernel.CondCdf
: these two files will later be refactored to use the code in this PR.