DDM RESPONSE_TIME Bug

[davidt0x]

Currently, on devel the RESPONSE_TIME output port of the integrator DDM appears to be bugged, but only in Python mode. The port mistakenly indicates that threshold was reached in a single step of integration. In compiled mode, the correct response time is returned. See example below.

import psyneulink as pnl

from psyneulink.core.globals.utilities import set_global_seed
set_global_seed(0)

my_ddm = pnl.DDM(
    function=pnl.DriftDiffusionIntegrator(
        starting_value=0,
        threshold=.1,
        noise=0.1,
        time_step_size=.1,
        non_decision_time=0
    ),
    reset_stateful_function_when=pnl.AtTrialStart(),
    output_ports=[pnl.DECISION_OUTCOME, pnl.RESPONSE_TIME],
    execute_until_finished=True,
    name="DDM"
)

comp = pnl.Composition()
comp.add_node(my_ddm)

comp.run(inputs=[.2])
# comp.run(inputs=[.2], execution_mode=pnl.ExecutionMode.LLVMRun)

print(comp.results)

Python Mode Output:

[[[1. ]
  [0.1]]]

Compiled Output:

[[[1. ]
  [0.5]]]