From 0a140864f8d11215c0d7e756d1b43d2bea6aafc1 Mon Sep 17 00:00:00 2001
From: Hong Ge <h.ge@damtp.cam.ac.uk>
Date: Tue, 9 May 2017 09:11:37 +0100
Subject: [PATCH] Fix PG (#247)

---
 src/samplers/pgibbs.jl | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/samplers/pgibbs.jl b/src/samplers/pgibbs.jl
index 21dad8d31b..11669cfd98 100644
--- a/src/samplers/pgibbs.jl
+++ b/src/samplers/pgibbs.jl
@@ -50,6 +50,7 @@ step(model::Function, spl::Sampler{PG}, vi::VarInfo, _::Bool) = step(model, spl,
 step(model::Function, spl::Sampler{PG}, vi::VarInfo) = begin
   particles = ParticleContainer{TraceR}(model)
 
+  vi.index = 0; vi.num_produce = 0;  # We need this line cause fork2 deepcopy `vi`. 
   ref_particle = isempty(vi) ?
                  nothing :
                  fork2(TraceR(model, spl, vi))