RecSim_FlashcardLearning/user/FlashcardUserModel.py

67 lines
2.8 KiB
Python

from recsim import user
from recsim.choice_model import MultinomialLogitChoiceModel
from .UserState import UserState
from .UserSampler import UserSampler
from .UserResponse import UserResponse
from util import eval_result
import numpy as np
class FlashcardUserModel(user.AbstractUserModel):
def __init__(self, num_candidates, time_budget, slate_size, seed=0, sample_seed=0):
super(FlashcardUserModel, self).__init__(
UserResponse, UserSampler(
UserState, num_candidates, time_budget,
seed=sample_seed
), slate_size)
self.choice_model = MultinomialLogitChoiceModel({})
self._rng = np.random.RandomState(seed)
def is_terminal(self):
terminated = self._user_state._time > self._user_state._time_budget
if terminated: # run evaluation process
eval_result(self._user_state._time,
self._user_state._last_review.copy(),
self._user_state._history.copy(),
self._user_state._W.copy())
return terminated
def update_state(self, slate_documents, responses):
for doc, response in zip(slate_documents, responses):
doc_id = doc._doc_id
self._user_state._history[doc_id][0] += 1
if response._recall:
self._user_state._history[doc_id][1] += 1
else:
self._user_state._history[doc_id][2] += 1
self._user_state._last_review[doc_id] = self._user_state._time
self._user_state._time += 1
def simulate_response(self, slate_documents):
responses = [self._response_model_ctor() for _ in slate_documents]
# Get click from of choice model.
self.choice_model.score_documents(
self._user_state, [doc.create_observation() for doc in slate_documents])
scores = self.choice_model.scores
selected_index = self.choice_model.choose_item()
# Populate clicked item.
self._generate_response(slate_documents[selected_index],
responses[selected_index])
return responses
def _generate_response(self, doc, response):
# W = np.array([1,1,1])
doc_id = doc._doc_id
W = self._user_state._W[doc_id]
if not W.any(): # uninitialzed
error = self._user_state._doc_error[doc_id] # a uniform error for each user
self._user_state._W[doc_id] = W = doc.base_difficulty * error
print(W)
# use exponential function to simulate whether the user recalls
last_review = self._user_state._time - self._user_state._last_review[doc_id]
x = self._user_state._history[doc_id]
pr = np.exp(-last_review / np.exp(np.dot(W, x))).squeeze()
print(f"time: {self._user_state._time}, reviewing flashcard {doc_id}, recall rate = {pr}")
if self._rng.random_sample() < pr: # remembered
response._recall = True
response._pr = pr