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Simplistic ZigZag for Soss
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using Soss: logdensity, xform, ConditionalModel | |
using ZigZagBoomerang | |
using ForwardDiff | |
using ForwardDiff: gradient! | |
using LinearAlgebra | |
using SparseArrays | |
using StructArrays | |
using TransformVariables | |
Soss.xform(m::SpikeMixture) = Soss.xform(m.m) | |
kappa(m::SpikeMixture{WeightedMeasure{Float64,Lebesgue{ℝ}},Float64}) = 1/(1/m.w - 1) | |
kappa(m::WeightedMeasure{Float64,Lebesgue{ℝ}}) = Inf | |
Soss.xform(m::SpikeMixture) = Soss.xform(m.m) | |
function sparse_zigzag(m::ConditionalModel, T = 1000.0; c=10.0, adapt=false) | |
ℓ(pars) = logdensity(m, pars) | |
t = xform(m) | |
function f(x) | |
(θ, logjac) = TransformVariables.transform_and_logjac(t, x) | |
-ℓ(θ) - logjac | |
end | |
d = t.dimension | |
function partiali() | |
ith = zeros(d) | |
function (x,i) | |
ith[i] = 1 | |
sa = StructArray{ForwardDiff.Dual{}}((x, ith)) | |
δ = f(sa).partials[] | |
ith[i] = 0 | |
return δ | |
end | |
end | |
∇ϕi = partiali() | |
# Draw a random starting points and velocity | |
tkeys = keys(t(zeros(d))) | |
vars = Soss.select(rand(m), tkeys) | |
bm_ = Soss.basemeasure(m, vars) | |
bm = getindex.(Ref(bm_.data), (keys(vars))) | |
κ = kappa.(bm) | |
t0 = 0.0 | |
x0 = inverse(t, vars) | |
θ0 = randn(d) | |
sspdmp(∇ϕi, t0, x0, θ0, T, c*ones(d), ZigZag(sparse(I(d)), 0*x0), κ; adapt=adapt) | |
end | |
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using Soss: logdensity, xform, ConditionalModel | |
using ZigZagBoomerang | |
using ForwardDiff | |
using ForwardDiff: gradient! | |
using LinearAlgebra | |
using SparseArrays | |
using StructArrays | |
using TransformVariables | |
Soss.xform(m::SpikeMixture) = Soss.xform(m.m) | |
function zigzag(m::ConditionalModel, T = 1000.0; c=10.0, adapt=false) | |
ℓ(pars) = logdensity(m, pars) | |
t = xform(m) | |
function f(x) | |
(θ, logjac) = TransformVariables.transform_and_logjac(t, x) | |
-ℓ(θ) - logjac | |
end | |
d = t.dimension | |
function partiali() | |
ith = zeros(d) | |
function (x,i) | |
ith[i] = 1 | |
sa = StructArray{ForwardDiff.Dual{}}((x, ith)) | |
δ = f(sa).partials[] | |
ith[i] = 0 | |
return δ | |
end | |
end | |
∇ϕi = partiali() | |
# Draw a random starting points and velocity | |
tkeys = keys(t(zeros(d))) | |
vars = Soss.select(rand(m), tkeys) | |
t0 = 0.0 | |
x0 = inverse(t, vars) | |
θ0 = randn(d) | |
pdmp(∇ϕi, t0, x0, θ0, T, c*ones(d), ZigZag(sparse(I(d)), 0*x0); adapt=adapt) | |
end | |
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