simple scheduling model

Author: Theodore-Chatziioannou

.gitignore

@@ -38,4 +38,5 @@ mike-*.yml
 .ipynb_checkpoints
 examples
 **/outputs/
-**/tmp/
+**/tmp/
+temp/

requirements/base.txt

@@ -12,7 +12,9 @@ prettytable >= 3, < 4
 python-Levenshtein >= 0.21, < 0.26
 rich >= 12, < 14
 Rtree >= 1, < 2
+seaborn
 s2sphere < 0.3
 scikit-learn >= 1.2, < 2
 shapely >= 1, < 3
+tensforflow
 xlrd >= 2, < 3

src/pam/planner/choice_scheduling.py

@@ -0,0 +1,68 @@
+from typing import Optional
+
+import numpy as np
+from tensorflow import keras
+
+from pam.core import Population
+from pam.planner.encoder import PlansSequenceEncoder
+
+
+class ScheduleModelSimple:
+    def __init__(
+        self, population: Population, n_units: Optional[int] = 50, dropout: Optional[float] = 0.1
+    ) -> None:
+        self.encoder = PlansSequenceEncoder(population=population)
+
+        # build model
+        input_acts = keras.layers.Input(shape=[self.encoder.acts.shape[1]])
+        emb_acts = keras.layers.Embedding(
+            len(self.encoder.activity_encoder.labels), 1, mask_zero=True, name="emb"
+        )(input_acts)
+        encoder_h1, encoder_h, encoder_c = keras.layers.LSTM(
+            n_units, return_state=True, name="encoder_h1"
+        )(emb_acts)
+        encoder_state = [encoder_h, encoder_c]
+
+        decoder_input = keras.layers.Input(shape=[self.encoder.durations.shape[1] - 1, 1])
+        decoder_h1 = keras.layers.LSTM(
+            n_units, name="decoder_h1", dropout=dropout, return_sequences=True
+        )(decoder_input, initial_state=encoder_state)
+        decoder_h2 = keras.layers.LSTM(
+            n_units, name="decoder_h2", dropout=dropout, return_sequences=True
+        )(decoder_h1)
+        decoder_output = keras.layers.Dense(1, activation="relu", name="decoder_output")(decoder_h2)
+        model = keras.models.Model(inputs=[input_acts, decoder_input], outputs=[decoder_output])
+
+        model.compile(loss="mean_squared_error", optimizer="adam", metrics=["accuracy"])
+        model.summary()
+
+        self.model = model
+
+    def fit(self, epochs: int = 500) -> None:
+        """Fit the sceduling model.
+
+        Args:
+            epochs (int, optional): Number of epochs to run. Defaults to 500.
+        """
+        X = self.encoder.acts[:, ::-1]
+        durations = self.encoder.durations
+        self.history = self.model.fit([X, durations[:, :-1]], durations[:, 1:], epochs=epochs)
+
+    def predict(self, population: Population) -> np.array:
+        """Predict the activity durations of a population.
+
+        Args:
+            population (Population): A PAM population.
+
+        Returns:
+            np.array: Durations array. Each row represents a plan.
+        """
+        encoder = PlansSequenceEncoder(
+            population=population, activity_encoder=self.encoder.activity_encoder
+        )
+        X = encoder.acts[:, ::-1]
+        y_pred = np.zeros(shape=encoder.durations.shape)
+        for i in range(1, y_pred.shape[1]):
+            y_pred[:, i] = self.model.predict([X, y_pred[:, :i]])[:, -1, 0]
+
+        return y_pred

src/pam/planner/encoder.py

@@ -4,22 +4,24 @@
 
 if TYPE_CHECKING:
     from pam.activity import Plan
+    from pam.core import Population
 
 from datetime import timedelta as td
 from itertools import groupby
 from typing import List, Optional, Union
 
 import numpy as np
+import pandas as pd
 
 from pam import activity
 from pam.variables import START_OF_DAY
 
 
 class Encoder:
     def __init__(self, labels: List[str], travel_act="travel") -> None:
-        self.labels = set(labels)
+        self.labels = list(labels)
         if travel_act not in self.labels:
-            self.labels.add(travel_act)
+            self.labels.append(travel_act)
         self.label_code = self.get_mapping(self.labels)
         self.code_label = {v: k for k, v in self.label_code.items()}
 
@@ -169,3 +171,63 @@ class PlansOneHotEncoder(PlansEncoder):
     """
 
     plans_encoder_class = PlanOneHotEncoder
+
+
+class PlansSequenceEncoder:
+    def __init__(self, population: Population, activity_encoder: Optional[Encoder] = None) -> None:
+        """Encodes the plans of a population into arrays representing sequencies of activities and durations.
+
+        Args:
+            population (Population): A PAM population.
+            activity_encoder (Optional[Encoder], optional): Encoder of activity types. Defaults to None.
+        """
+
+        self.population = population
+        act_labels = ["NA", "SOS", "EOS"] + list(population.activity_classes)
+
+        if activity_encoder is None:
+            self.activity_encoder = StringIntEncoder(act_labels)
+        else:
+            self.activity_encoder = activity_encoder
+
+        self.acts = None
+        self.acts_labels = None
+        self.durations = None
+
+        self.encode_plans()
+
+    def encode_plans(self) -> None:
+        """Encode sequencies of activities and durations into numpy arrays."""
+        acts = []
+        acts_labels = []
+        durations = []
+        for hid, pid, person in self.population.people():
+            # start-of-sequence values
+            person_acts = [1]
+            person_acts_labels = []
+            person_durations = [0]
+
+            # collect activities and durations
+            for act in person.activities:
+                person_acts.append(self.activity_encoder.encode(act.act))
+                person_acts_labels.append(act.act)
+                person_durations.append(act.duration / pd.Timedelta(hours=24))
+
+            # end-of-sequence values
+            person_acts.append(2)
+            person_durations.append(0)
+
+            # append
+            acts.append(person_acts)
+            acts_labels.append(person_acts_labels)
+            durations.append(person_durations)
+
+        # convert to arrays
+        acts = pd.DataFrame(acts).fillna(0).values.astype(int)
+        durations = pd.DataFrame(durations).fillna(0).values
+        durations = durations / durations.sum(1).reshape(-1, 1)  # add up to 24 hours
+
+        # store
+        self.acts = acts
+        self.acts_labels = acts_labels
+        self.durations = durations

tests/conftest.py

@@ -1120,6 +1120,14 @@ def population_no_args(test_trips_pathv12):
     return read.read_matsim(test_trips_pathv12, version=12)
 
 
+@pytest.fixture()
+def population_simple():
+    df_diaries = pd.read_csv(TEST_DATA_DIR / "simple_travel_diaries.csv")
+    df_persons = pd.read_csv(TEST_DATA_DIR / "simple_persons_data.csv")
+    population = read.load_travel_diary(trips=df_diaries, persons_attributes=df_persons)
+    return population
+
+
 @pytest.fixture
 def population_experienced(test_experienced_pathv12):
     return read.read_matsim(test_experienced_pathv12, version=12)

tests/test_29_planner_scheduling.py

@@ -0,0 +1,24 @@
+import numpy as np
+import pytest
+from pam.planner.choice_scheduling import ScheduleModelSimple
+from tensorflow import keras
+
+
+@pytest.fixture
+def model_simple(population_simple) -> ScheduleModelSimple:
+    return ScheduleModelSimple(population_simple)
+
+
+def test_start_end_tokens(model_simple):
+    assert model_simple.encoder.activity_encoder.label_code["SOS"] == 1
+    assert model_simple.encoder.activity_encoder.label_code["EOS"] == 2
+
+
+def test_prediction_shape_matches_input(model_simple, population_simple):
+    model_simple.fit(epochs=2)
+    y_pred = model_simple.predict(population_simple)
+    np.testing.assert_equal(y_pred.shape, model_simple.encoder.durations.shape)
+
+
+def test_model_built(model_simple):
+    assert isinstance(model_simple.model, keras.models.Model)