OWSGD: Output coefficients

Author: VesnaT

Orange/widgets/classify/tests/test_owsgd.py

@@ -1,5 +1,6 @@
 # Test methods with long descriptive names can omit docstrings
 # pylint: disable=missing-docstring
+from Orange.data import Table
 from Orange.widgets.classify.owsgd import OWSGD
 from Orange.widgets.tests.base import WidgetTest, WidgetLearnerTestMixin, \
     ParameterMapping
@@ -23,3 +24,16 @@ def setUp(self):
             ParameterMapping.from_attribute(self.widget, 'eta0'),
             ParameterMapping.from_attribute(self.widget, 'power_t'),
         ]
+
+    def test_output_coefficients(self):
+        """Check if coefficients are on output after apply"""
+        self.assertIsNone(self.get_output("Coefficients"))
+        self.send_signal("Data", self.data)
+        self.widget.apply_button.button.click()
+        coeffs = self.get_output("Coefficients")
+        self.assertIsInstance(coeffs, Table)
+        domain = self.data.domain
+        self.assertEqual(coeffs.X.shape, (len(domain.attributes) + 1,
+                                          len(domain.class_var.values)))
+        self.send_signal("Data", None)
+        self.assertIsNone(self.get_output("Coefficients"))

Orange/widgets/model/owsgd.py

@@ -3,8 +3,10 @@
 from AnyQt.QtCore import Qt
 
 from Orange.canvas.report import bool_str
+from Orange.data import ContinuousVariable, StringVariable, Domain, Table
 from Orange.modelling.linear import SGDLearner
-from Orange.widgets import gui
+from Orange.widgets import gui, widget
+from Orange.widgets.classify.owlogisticregression import create_coef_table
 from Orange.widgets.settings import Setting
 from Orange.widgets.utils.owlearnerwidget import OWBaseLearner
 
@@ -20,6 +22,8 @@ class OWSGD(OWBaseLearner):
 
     LEARNER = SGDLearner
 
+    outputs = [("Coefficients", Table, widget.Explicit)]
+
     reg_losses = (
         ('Squared Loss', 'squared_loss'),
         ('Huber', 'huber'),
@@ -281,6 +285,22 @@ def get_learner_parameters(self):
 
         return list(params.items())
 
+    def update_model(self):
+        super().update_model()
+        coeffs = None
+        if self.model is not None:
+            if self.model.domain.class_var.is_discrete:
+                coeffs = create_coef_table(self.model)
+            else:
+                attrs = [ContinuousVariable("coef", number_of_decimals=7)]
+                domain = Domain(attrs, metas=[StringVariable("name")])
+                cfs = list(self.model.intercept) + list(self.model.coefficients)
+                names = ["intercept"] + \
+                        [attr.name for attr in self.model.domain.attributes]
+                coeffs = Table(domain, list(zip(cfs, names)))
+                coeffs.name = "coefficients"
+        self.send("Coefficients", coeffs)
+
 
 if __name__ == '__main__':
     import sys

Orange/widgets/regression/tests/test_owsgdregression.py

@@ -1,5 +1,6 @@
 # Test methods with long descriptive names can omit docstrings
 # pylint: disable=missing-docstring
+from Orange.data import Table
 from Orange.widgets.regression.owsgdregression import OWSGD
 from Orange.widgets.tests.base import WidgetTest, WidgetLearnerTestMixin, \
     ParameterMapping
@@ -24,3 +25,15 @@ def setUp(self):
             ParameterMapping.from_attribute(self.widget, 'eta0'),
             ParameterMapping.from_attribute(self.widget, 'power_t'),
         ]
+
+    def test_output_coefficients(self):
+        """Check if coefficients are on output after apply"""
+        self.assertIsNone(self.get_output("Coefficients"))
+        self.send_signal("Data", self.data)
+        self.widget.apply_button.button.click()
+        coeffs = self.get_output("Coefficients")
+        self.assertIsInstance(coeffs, Table)
+        self.assertEqual(coeffs.X.shape,
+                         (len(self.data.domain.attributes) + 1, 1))
+        self.send_signal("Data", None)
+        self.assertIsNone(self.get_output("Coefficients"))