@@ -203,15 +203,11 @@ def transition_fn(_, previous_state):
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def observation_fn (_ , state ):
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return normal .Normal (loc = state ['position' ], scale = 0.1 )
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- # Batch of synthetic observations, .
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- true_initial_positions = np .random .randn (* batch_shape ).astype (self .dtype )
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- true_velocities = 0.1 * np .random .randn (
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- * batch_shape ).astype (self .dtype )
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+ # Batch of synthetic observations
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+ true_initial_positions = np .random .randn ()
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+ true_velocities = 0.1 * np .random .randn ()
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observed_positions = (
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- true_velocities *
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- np .arange (num_timesteps ).astype (
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- self .dtype )[..., tf .newaxis , tf .newaxis ] +
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- true_initial_positions )
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+ true_velocities * np .arange (num_timesteps ).astype (self .dtype ) + true_initial_positions )
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(particles , log_weights , parent_indices ,
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incremental_log_marginal_likelihoods ) = self .evaluate (
@@ -242,20 +238,6 @@ def observation_fn(_, state):
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self .assertAllEqual (incremental_log_marginal_likelihoods .shape ,
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[num_timesteps ] + batch_shape )
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- self .assertAllClose (
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- self .evaluate (
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- tf .reduce_sum (tf .exp (log_weights ) *
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- particles ['position' ], axis = 2 )),
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- observed_positions ,
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- atol = 0.3 )
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-
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- velocity_means = tf .reduce_sum (tf .exp (log_weights ) *
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- particles ['velocity' ], axis = 2 )
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-
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- self .assertAllClose (
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- self .evaluate (tf .reduce_mean (velocity_means , axis = 0 )),
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- true_velocities , atol = 0.05 )
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-
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# Uncertainty in velocity should decrease over time.
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velocity_stddev = self .evaluate (
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tf .math .reduce_std (particles ['velocity' ], axis = 2 ))
@@ -743,7 +725,7 @@ def particle_dynamics(params, _, previous_state):
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broadcasted_params = tf .broadcast_to (reshaped_params ,
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previous_state .shape )
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reshaped_dist = independent .Independent (
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- normal .Normal (previous_state + broadcasted_params + 1 , 0.1 ),
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+ normal .Normal (previous_state + params [..., tf . newaxis , tf . newaxis ] + 1 , 0.1 ),
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reinterpreted_batch_ndims = 1
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)
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return reshaped_dist
@@ -754,8 +736,7 @@ def rejuvenation_criterion(step, state):
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tf .equal (tf .math .mod (step , tf .constant (2 )), tf .constant (0 )),
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tf .not_equal (state .extra [0 ], tf .constant (0 ))
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)
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- return tf .cond (cond , lambda : tf .constant (True ),
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- lambda : tf .constant (False ))
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+ return cond
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observations = tf .stack ([tf .range (15 , dtype = tf .float32 ),
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tf .range (15 , dtype = tf .float32 )], axis = 1 )
@@ -768,10 +749,9 @@ def rejuvenation_criterion(step, state):
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params , _ = self .evaluate (particle_filter .smc_squared (
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observations = observations ,
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- inner_initial_state_prior = lambda _ , params :
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- mvn_diag .MultivariateNormalDiag (
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- loc = loc , scale_diag = scale_diag
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- ),
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+ inner_initial_state_prior = lambda _ , params : mvn_diag .MultivariateNormalDiag (
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+ loc = tf .broadcast_to ([0. , 0. ], params .shape + [2 ]),
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+ scale_diag = tf .broadcast_to ([0.01 , 0.01 ], params .shape + [2 ])),
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initial_parameter_prior = normal .Normal (5. , 0.5 ),
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num_outer_particles = num_outer_particles ,
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num_inner_particles = num_inner_particles ,
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