Validation period

README.md

@@ -125,7 +125,7 @@ You can estimate the causal effect of the intervention using the `estimate_effec
 
 ```python
 >>> sc.estimate_effects()
-0.8398940970771678
+[0.8398940970771678]
 ```
 
 ### Placebo Test

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "synthx"
-version = "0.4.3"
+version = "1.0.0"
 description = "A Python Library for Advanced Synthetic Control Analysis"
 authors = ["kenki931128 <kenki.nkmr@gmail.com>"]
 license = "MIT License"

synthx/core/dataset.py

@@ -30,6 +30,7 @@ def __init__(
         covariate_columns: Optional[list[str]],
         intervention_units: Union[Any, list[Any]],
         intervention_time: Union[int, date],
+        validation_time: Optional[Union[int, date]] = None,
         norm: Optional[str] = None,
     ) -> None:
         """Initialize the Dataset.
@@ -42,6 +43,7 @@ def __init__(
             covariate_columns (Optional[list[str]]): The columns representing the covariates.
             intervention_units (Union[Any, list[Any]]): A list of intervented units
             intervention_time (Union[int, date]): When the intervention or event happens.
+            validation_time (Optional[Union[int, date]]): validation time if needed.
             norm (Optional[str]): If not None, will normalize the y_column.
                 it should be 'z_standardize'
         """
@@ -54,6 +56,7 @@ def __init__(
             intervention_units if isinstance(intervention_units, list) else [intervention_units]
         )
         self.intervention_time = intervention_time
+        self.validation_time = validation_time
         self.norm = norm
         self.__validate()
         self.__normalization()
@@ -71,7 +74,12 @@ def plot(self, units: Optional[list[str]] = None, save: Optional[str] = None) ->
         for unit in units:
             unit_data = self.data.filter(pl.col(self.unit_column) == unit)
             plt.plot(unit_data[self.time_column], unit_data[self.y_column], label=f'Unit {unit}')
-        # Add vertical line for intervention time
+
+        # Add vertical line for validation time and intervention time
+        if self.validation_time is not None:
+            plt.axvline(
+                self.validation_time, color='orange', linestyle='--', label='Validation Time'  # type: ignore
+            )
         plt.axvline(
             self.intervention_time, color='red', linestyle='--', label='Intervention Time'  # type: ignore
         )
@@ -117,6 +125,16 @@ def __validate(self) -> None:
             )
         if self.intervention_time > self.data[self.time_column].max():  # type: ignore
             raise InvalidInterventionTimeError(f'no date point at {self.intervention_time} time.')
+        if self.validation_time is not None and type(self.intervention_time) != type(
+            self.validation_time
+        ):
+            raise InvalidColumnTypeError(
+                f'intervention_time and validation_time should have the same type.'
+            )
+        if self.validation_time is not None and self.intervention_time <= self.validation_time:  # type: ignore
+            raise InvalidInterventionTimeError(
+                f'intervention_time should be later than validation_time.'
+            )
 
         if self.y_column not in self.data.columns:
             raise ColumnNotFoundError(self.y_column)

synthx/core/result.py

@@ -103,9 +103,14 @@ def estimate_effects(self) -> list[float]:
         Returns:
             list[float]: The estimated effect of the intervention.
         """
-        # dataset before intervention
+        # dataset in the training period
+        training_time = (
+            self.dataset.validation_time
+            if self.dataset.validation_time is not None
+            else self.dataset.intervention_time
+        )
         pre_df = self.dataset.data.filter(
-            self.dataset.data[self.dataset.time_column] < self.dataset.intervention_time
+            self.dataset.data[self.dataset.time_column] < training_time
         )
         pre_result = SyntheticControlResult(
             dataset=sx.Dataset(
@@ -159,6 +164,13 @@ def plot(self, save: Optional[str] = None) -> None:
         for i, intervention_unit in enumerate(self.dataset.intervention_units):
             axs[i].plot(self.x_time, self.y_test(intervention_unit), label='Test')
             axs[i].plot(self.x_time, self.y_control(intervention_unit), label='Control')
+            if self.dataset.validation_time is not None:
+                axs[i].axvline(
+                    self.dataset.validation_time,
+                    color='orange',
+                    linestyle='--',
+                    label='Validation Time',
+                )
             axs[i].axvline(
                 self.dataset.intervention_time,
                 color='red',

synthx/method.py

@@ -43,8 +43,12 @@ def synthetic_control(dataset: sx.Dataset) -> sx.SyntheticControlResult:
     df = dataset.data
 
     # condition
-    # TODO: add validation period
-    condition_pre_intervention_time = df[dataset.time_column] < dataset.intervention_time
+    training_time = (
+        dataset.validation_time
+        if dataset.validation_time is not None
+        else dataset.intervention_time
+    )
+    condition_training_time = df[dataset.time_column] < training_time
     condition_control_units = ~df[dataset.unit_column].is_in(dataset.intervention_units)
 
     # weights for variables and scale each variables
@@ -64,12 +68,12 @@ def synthetic_control(dataset: sx.Dataset) -> sx.SyntheticControlResult:
         )
 
     # dataframe for control
-    df_control = df.filter(condition_pre_intervention_time & condition_control_units)
+    df_control = df.filter(condition_training_time & condition_control_units)
 
     control_unit_weights: list[np.ndarray] = []
     for intervention_unit in dataset.intervention_units:
         condition_test_unit = df[dataset.unit_column] == intervention_unit
-        df_test = df.filter(condition_pre_intervention_time & condition_test_unit)
+        df_test = df.filter(condition_training_time & condition_test_unit)
 
         # optimize unit weights
         def objective(unit_weights: np.ndarray) -> float:
@@ -182,6 +186,7 @@ def process_placebo(
             covariate_columns=dataset.covariate_columns,
             intervention_units=test_unit_placebo,
             intervention_time=dataset.intervention_time,
+            validation_time=dataset.validation_time,
         )
         try:
             sc_placebo = synthetic_control(dataset_placebo)
@@ -246,6 +251,7 @@ def sensitivity_check(
             covariate_columns=dataset.covariate_columns,
             intervention_units=dataset.intervention_units,
             intervention_time=dataset.intervention_time,
+            validation_time=dataset.validation_time,
         )
 
         try:

tests/core/test_dataset.py

@@ -59,6 +59,19 @@ def test_init_single_intervention_unit(self, sample_data: pl.DataFrame) -> None:
         )
         assert dataset.intervention_units == [1]
 
+    def test_init_with_validation_time(self, sample_data: pl.DataFrame) -> None:
+        dataset = sx.Dataset(
+            data=sample_data,
+            unit_column='unit',
+            time_column='time',
+            y_column='y',
+            covariate_columns=['cov1', 'cov2'],
+            intervention_units=1,
+            intervention_time=3,
+            validation_time=2,
+        )
+        assert dataset.validation_time == 2
+
     def test_plot(self, sample_data: pl.DataFrame, mocker: MockerFixture) -> None:
         dataset = sx.Dataset(
             data=sample_data,
@@ -160,6 +173,21 @@ def test_validate_invalid_intervention_time(self, sample_data: pl.DataFrame) ->
                 intervention_time=4,
             )
 
+    def test_validate_invalid_intervention_time_vs_validation_time(
+        self, sample_data: pl.DataFrame
+    ) -> None:
+        with pytest.raises(InvalidInterventionTimeError):
+            sx.Dataset(
+                data=sample_data,
+                unit_column='unit',
+                time_column='time',
+                y_column='y',
+                covariate_columns=['cov1', 'cov2'],
+                intervention_units=[1],
+                intervention_time=4,
+                validation_time=5,
+            )
+
     def test_validate_missing_y_column(self, sample_data: pl.DataFrame) -> None:
         with pytest.raises(ColumnNotFoundError):
             sx.Dataset(