feat: add flag to disable gathering of particles in smc

Author: alecksphillips

discretesampling/base/algorithms/smc.py

@@ -29,7 +29,7 @@ def __init__(self, variableType, target, initialProposal,
         self.initialProposal = initialProposal
         self.target = target
 
-    def sample(self, Tsmc, N, seed=0):
+    def sample(self, Tsmc, N, seed=0, gather_results=True):
         loc_n = int(N/self.exec.P)
         rank = self.exec.rank
         mvrs_rng = RNG(seed)
@@ -75,8 +75,9 @@ def sample(self, Tsmc, N, seed=0):
 
             current_particles = new_particles
 
-        current_particles = self.exec.gather_all(current_particles)
-        logWeights = self.exec.gather(logWeights, [N])
+        if gather_results:
+            current_particles = self.exec.gather_all(current_particles)
+            logWeights = self.exec.gather(logWeights, [N])
         results = SMCOutput(current_particles, logWeights)
 
         return results