Allow external preprocessors

Author: AndrejaKovacic

Orange/widgets/model/owsvm.py

@@ -31,10 +31,12 @@ class OWSVM(OWBaseLearner):
     pps = SklLearner.preprocessors
     scaling = [Scale(center=Scale.NoCentering)]
 
+    def __init__(self):
+        super().__init__(SklLearner.preprocessors)
+
     class Outputs(OWBaseLearner.Outputs):
         support_vectors = Output("Support vectors", Table, explicit=True)
 
-
     #: Different types of SVMs
     SVM, Nu_SVM = range(2)
     #: SVM type
@@ -71,6 +73,13 @@ class Outputs(OWBaseLearner.Outputs):
                ("RBF", "exp(-g|x-y|²)"),
                ("Sigmoid", "tanh(g x⋅y + c)"))
 
+    def set_preprocessor(self, preprocessor):
+        if preprocessor is None:
+            self.preprocessors = self.pps
+        else:
+            self.preprocessors = preprocessor
+        self.apply()
+
     def add_main_layout(self):
         self._add_type_box()
         self._add_kernel_box()
@@ -222,7 +231,7 @@ def create_learner(self):
             'probability': True,
             'tol': self.tol,
             'max_iter': self.max_iter if self.limit_iter else -1,
-            'preprocessors': self.pps + self.scaling if self.scale_data else self.pps
+            'preprocessors': self.preprocessors + self.scaling if self.scale_data else self.preprocessors
         }
         if self.svm_type == self.SVM:
             return SVMLearner(C=self.C, epsilon=self.epsilon, **common_args)

Orange/widgets/utils/owlearnerwidget.py

@@ -90,15 +90,15 @@ class Outputs:
 
     OUTPUT_MODEL_NAME = Outputs.model.name  # Attr for backcompat w/ self.send() code
 
-    def __init__(self):
+    def __init__(self, preprocessors=None):
         super().__init__()
         self.data = None
         self.valid_data = False
         self.learner = None
         if self.learner_name is None:
             self.learner_name = self.name
         self.model = None
-        self.preprocessors = None
+        self.preprocessors = preprocessors
         self.outdated_settings = False
 
         self.setup_layout()