Enable option zipmap for LGBM converter (fix issue #451)

onnxmltools/convert/lightgbm/_parse.py

@@ -87,11 +87,13 @@ def _parse_lightgbm_simple_model(scope, model, inputs):
     return this_operator.outputs
 
 
-def _parse_sklearn_classifier(scope, model, inputs):
+def _parse_sklearn_classifier(scope, model, inputs, zipmap=True):
     probability_tensor = _parse_lightgbm_simple_model(
         scope, model, inputs)
     this_operator = scope.declare_local_operator('LgbmZipMap')
     this_operator.inputs = probability_tensor
+    this_operator.zipmap = zipmap
+
     classes = model.classes_
     label_type = Int64Type()
 
@@ -116,33 +118,39 @@ def _parse_sklearn_classifier(scope, model, inputs):
         label_type = StringType()
 
     output_label = scope.declare_local_variable('label', label_type)
-    output_probability = scope.declare_local_variable(
-        'probabilities',
-        SequenceType(DictionaryType(label_type, FloatTensorType())))
+    if zipmap:
+        output_probability = scope.declare_local_variable(
+            'probabilities',
+            SequenceType(DictionaryType(label_type, FloatTensorType())))
+    else:
+        output_probability = scope.declare_local_variable(
+            'probabilities', FloatTensorType())
     this_operator.outputs.append(output_label)
     this_operator.outputs.append(output_probability)
     return this_operator.outputs
 
 
-def _parse_lightgbm(scope, model, inputs):
+def _parse_lightgbm(scope, model, inputs, zipmap=True):
     '''
     This is a delegate function. It doesn't nothing but invoke the correct parsing function according to the input
     model's type.
     :param scope: Scope object
     :param model: A lightgbm object
     :param inputs: A list of variables
+    :param zipmap: add operator ZipMap after operator TreeEnsembleClassifier
     :return: The output variables produced by the input model
     '''
     if isinstance(model, LGBMClassifier):
-        return _parse_sklearn_classifier(scope, model, inputs)
+        return _parse_sklearn_classifier(scope, model, inputs, zipmap=zipmap)
     if (isinstance(model, WrappedBooster) and
             model.operator_name == 'LgbmClassifier'):
-        return _parse_sklearn_classifier(scope, model, inputs)
+        return _parse_sklearn_classifier(scope, model, inputs, zipmap=zipmap)
     return _parse_lightgbm_simple_model(scope, model, inputs)
 
 
 def parse_lightgbm(model, initial_types=None, target_opset=None,
-                   custom_conversion_functions=None, custom_shape_calculators=None):
+                   custom_conversion_functions=None, custom_shape_calculators=None,
+                   zipmap=True):
     raw_model_container = LightGbmModelContainer(model)
     topology = Topology(raw_model_container, default_batch_size='None',
                         initial_types=initial_types, target_opset=target_opset,
@@ -157,9 +165,9 @@ def parse_lightgbm(model, initial_types=None, target_opset=None,
     for variable in inputs:
         raw_model_container.add_input(variable)
 
-    outputs = _parse_lightgbm(scope, model, inputs)
+    outputs = _parse_lightgbm(scope, model, inputs, zipmap=zipmap)
 
     for variable in outputs:
         raw_model_container.add_output(variable)
 
-    return topology
+    return topology

onnxmltools/convert/lightgbm/convert.py

@@ -15,7 +15,7 @@
 
 def convert(model, name=None, initial_types=None, doc_string='', target_opset=None,
             targeted_onnx=onnx.__version__, custom_conversion_functions=None,
-            custom_shape_calculators=None, without_onnx_ml=False):
+            custom_shape_calculators=None, without_onnx_ml=False, zipmap=True):
     '''
     This function produces an equivalent ONNX model of the given lightgbm model.
     The supported lightgbm modules are listed below.
@@ -34,6 +34,7 @@ def convert(model, name=None, initial_types=None, doc_string='', target_opset=No
     :param custom_conversion_functions: a dictionary for specifying the user customized conversion function
     :param custom_shape_calculators: a dictionary for specifying the user customized shape calculator
     :param without_onnx_ml: whether to generate a model composed by ONNX operators only, or to allow the converter
+    :param zipmap: remove operator ZipMap from the ONNX graph
     to use ONNX-ML operators as well.
     :return: An ONNX model (type: ModelProto) which is equivalent to the input lightgbm model
     '''
@@ -50,7 +51,8 @@ def convert(model, name=None, initial_types=None, doc_string='', target_opset=No
         name = str(uuid4().hex)
 
     target_opset = target_opset if target_opset else get_maximum_opset_supported()
-    topology = parse_lightgbm(model, initial_types, target_opset, custom_conversion_functions, custom_shape_calculators)
+    topology = parse_lightgbm(model, initial_types, target_opset, custom_conversion_functions,
+                              custom_shape_calculators, zipmap=zipmap)
     topology.compile()
     onnx_ml_model = convert_topology(topology, name, doc_string, target_opset, targeted_onnx)
 

onnxmltools/convert/lightgbm/operator_converters/LightGbm.py

@@ -4,7 +4,8 @@
 import numbers
 import numpy as np
 from collections import Counter
-from ...common._apply_operation import apply_div, apply_reshape, apply_sub, apply_cast, apply_identity
+from ...common._apply_operation import (
+    apply_div, apply_reshape, apply_sub, apply_cast, apply_identity, apply_clip)
 from ...common._registration import register_converter
 from ...common.tree_ensemble import get_default_tree_classifier_attribute_pairs
 from ....proto import onnx_proto
@@ -453,23 +454,32 @@ def str2number(val):
 
 def convert_lgbm_zipmap(scope, operator, container):
     zipmap_attrs = {'name': scope.get_unique_operator_name('ZipMap')}
-    to_type = onnx_proto.TensorProto.INT64
-
     if hasattr(operator, 'classlabels_int64s'):
         zipmap_attrs['classlabels_int64s'] = operator.classlabels_int64s
+        to_type = onnx_proto.TensorProto.INT64
     elif hasattr(operator, 'classlabels_strings'):
         zipmap_attrs['classlabels_strings'] = operator.classlabels_strings
         to_type = onnx_proto.TensorProto.STRING
-
+    else:
+        raise RuntimeError("Unknown class type.")
     if to_type == onnx_proto.TensorProto.STRING:
         apply_identity(scope, operator.inputs[0].full_name,
                        operator.outputs[0].full_name, container)
     else:
         apply_cast(scope, operator.inputs[0].full_name,
                    operator.outputs[0].full_name, container, to=to_type)
-    container.add_node('ZipMap', operator.inputs[1].full_name,
-                       operator.outputs[1].full_name,
-                       op_domain='ai.onnx.ml', **zipmap_attrs)
+
+    if operator.zipmap:
+        container.add_node('ZipMap', operator.inputs[1].full_name,
+                           operator.outputs[1].full_name,
+                           op_domain='ai.onnx.ml', **zipmap_attrs)
+    else:
+        # This should be apply_identity but optimization fails in
+        # onnxconverter-common when trying to remove identity nodes.
+        apply_clip(scope, operator.inputs[1].full_name,
+                   operator.outputs[1].full_name, container,
+                   min=np.array([0], dtype=np.float32),
+                   max=np.array([1], dtype=np.float32))
 
 
 register_converter('LgbmClassifier', convert_lightgbm)

onnxmltools/convert/main.py

@@ -52,13 +52,14 @@ def convert_catboost(model, name=None, initial_types=None, doc_string='', target
 
 def convert_lightgbm(model, name=None, initial_types=None, doc_string='', target_opset=None,
                      targeted_onnx=onnx.__version__, custom_conversion_functions=None,
-                     custom_shape_calculators=None, without_onnx_ml=False):
+                     custom_shape_calculators=None, without_onnx_ml=False, zipmap=True):
     if not utils.lightgbm_installed():
         raise RuntimeError('lightgbm is not installed. Please install lightgbm to use this feature.')
 
     from .lightgbm.convert import convert
     return convert(model, name, initial_types, doc_string, target_opset, targeted_onnx,
-                   custom_conversion_functions, custom_shape_calculators, without_onnx_ml)
+                   custom_conversion_functions, custom_shape_calculators, without_onnx_ml,
+                   zipmap=zipmap)
 
 
 def convert_sklearn(model, name=None, initial_types=None, doc_string='', target_opset=None,

onnxmltools/utils/tests_helper.py

@@ -191,7 +191,7 @@ def dump_data_and_model(data, model, onnx=None, basename="model", folder=None,
     return names
 
 
-def convert_model(model, name, input_types, without_onnx_ml=False):
+def convert_model(model, name, input_types, without_onnx_ml=False, **kwargs):
     """
     Runs the appropriate conversion method.
 
@@ -201,26 +201,26 @@ def convert_model(model, name, input_types, without_onnx_ml=False):
     from sklearn.base import BaseEstimator
     if model.__class__.__name__.startswith("LGBM"):
         from onnxmltools.convert import convert_lightgbm
-        model, prefix = convert_lightgbm(model, name, input_types, without_onnx_ml=without_onnx_ml), "LightGbm"
+        model, prefix = convert_lightgbm(model, name, input_types, without_onnx_ml=without_onnx_ml, **kwargs), "LightGbm"
     elif model.__class__.__name__.startswith("XGB"):
         from onnxmltools.convert import convert_xgboost
-        model, prefix = convert_xgboost(model, name, input_types), "XGB"
+        model, prefix = convert_xgboost(model, name, input_types, **kwargs), "XGB"
     elif model.__class__.__name__ == 'Booster':
         import lightgbm
         if isinstance(model, lightgbm.Booster):
             from onnxmltools.convert import convert_lightgbm
-            model, prefix = convert_lightgbm(model, name, input_types, without_onnx_ml=without_onnx_ml), "LightGbm"
+            model, prefix = convert_lightgbm(model, name, input_types, without_onnx_ml=without_onnx_ml, **kwargs), "LightGbm"
         else:
             raise RuntimeError("Unable to convert model of type '{0}'.".format(type(model)))
     elif model.__class__.__name__.startswith("CatBoost"):
         from onnxmltools.convert import convert_catboost
-        model, prefix = convert_catboost(model, name, input_types), "CatBoost"
+        model, prefix = convert_catboost(model, name, input_types, **kwargs), "CatBoost"
     elif isinstance(model, BaseEstimator):
         from onnxmltools.convert import convert_sklearn
-        model, prefix = convert_sklearn(model, name, input_types), "Sklearn"
+        model, prefix = convert_sklearn(model, name, input_types, **kwargs), "Sklearn"
     else:
         from onnxmltools.convert import convert_coreml
-        model, prefix = convert_coreml(model, name, input_types), "Cml"
+        model, prefix = convert_coreml(model, name, input_types, **kwargs), "Cml"
     if model is None:
         raise RuntimeError("Unable to convert model of type '{0}'.".format(type(model)))
     return model, prefix

tests/lightgbm/test_LightGbmTreeEnsembleConverters.py

@@ -5,10 +5,12 @@
 
 import lightgbm
 import numpy
+from numpy.testing import assert_almost_equal
 from lightgbm import LGBMClassifier, LGBMRegressor
 import onnxruntime
 from onnxmltools.convert.common.utils import hummingbird_installed
 from onnxmltools.convert.common.data_types import FloatTensorType
+from onnxmltools.convert import convert_lightgbm
 from onnxmltools.utils import dump_data_and_model
 from onnxmltools.utils import dump_binary_classification, dump_multiple_classification
 from onnxmltools.utils import dump_single_regression
@@ -32,6 +34,50 @@ def test_lightgbm_classifier_zipmap(self):
             model, 'dummy', input_types=[('X', FloatTensorType([None, X.shape[1]]))])
         assert "zipmap" in str(onx).lower()
 
+    def test_lightgbm_classifier_nozipmap(self):
+        X = [[0, 1], [1, 1], [2, 0], [1, 2], [1, 5], [6, 2]]
+        X = numpy.array(X, dtype=numpy.float32)
+        y = [0, 1, 0, 1, 1, 0]
+        model = LGBMClassifier(n_estimators=3, min_child_samples=1, max_depth=2)
+        model.fit(X, y)
+        onx = convert_model(
+            model, 'dummy', input_types=[('X', FloatTensorType([None, X.shape[1]]))],
+            zipmap=False)
+        assert "zipmap" not in str(onx).lower()
+        onxs = onx[0].SerializeToString()
+        try:
+            sess = onnxruntime.InferenceSession(onxs)
+        except Exception as e:
+            raise AssertionError(
+                "Model cannot be loaded by onnxruntime due to %r\n%s." % (
+                    e, onx[0]))
+        exp = model.predict(X), model.predict_proba(X)
+        got = sess.run(None, {'X': X})
+        assert_almost_equal(exp[0], got[0])
+        assert_almost_equal(exp[1], got[1])
+
+    def test_lightgbm_classifier_nozipmap2(self):
+        X = [[0, 1], [1, 1], [2, 0], [1, 2], [1, 5], [6, 2]]
+        X = numpy.array(X, dtype=numpy.float32)
+        y = [0, 1, 0, 1, 1, 0]
+        model = LGBMClassifier(n_estimators=3, min_child_samples=1, max_depth=2)
+        model.fit(X, y)
+        onx = convert_lightgbm(
+            model, 'dummy', initial_types=[('X', FloatTensorType([None, X.shape[1]]))],
+            zipmap=False)
+        assert "zipmap" not in str(onx).lower()
+        onxs = onx.SerializeToString()
+        try:
+            sess = onnxruntime.InferenceSession(onxs)
+        except Exception as e:
+            raise AssertionError(
+                "Model cannot be loaded by onnxruntime due to %r\n%s." % (
+                    e, onx[0]))
+        exp = model.predict(X), model.predict_proba(X)
+        got = sess.run(None, {'X': X})
+        assert_almost_equal(exp[0], got[0])
+        assert_almost_equal(exp[1], got[1])
+
     def test_lightgbm_regressor(self):
         model = LGBMRegressor(n_estimators=3, min_child_samples=1)
         dump_single_regression(model)
@@ -58,6 +104,22 @@ def test_lightgbm_booster_classifier(self):
                             allow_failure="StrictVersion(onnx.__version__) < StrictVersion('1.3.0')",
                             basename=prefix + "BoosterBin" + model.__class__.__name__)
 
+    def test_lightgbm_booster_classifier_nozipmap(self):
+        X = [[0, 1], [1, 1], [2, 0], [1, 2]]
+        X = numpy.array(X, dtype=numpy.float32)
+        y = [0, 1, 0, 1]
+        data = lightgbm.Dataset(X, label=y)
+        model = lightgbm.train({'boosting_type': 'gbdt', 'objective': 'binary',
+                                'n_estimators': 3, 'min_child_samples': 1},
+                               data)
+        model_onnx, prefix = convert_model(model, 'tree-based classifier',
+                                           [('input', FloatTensorType([None, 2]))],
+                                           zipmap=False)
+        assert "zipmap" not in str(model_onnx).lower()
+        dump_data_and_model(X, model, model_onnx,
+                            allow_failure="StrictVersion(onnx.__version__) < StrictVersion('1.3.0')",
+                            basename=prefix + "BoosterBin" + model.__class__.__name__)
+
     def test_lightgbm_booster_classifier_zipmap(self):
         X = [[0, 1], [1, 1], [2, 0], [1, 2]]
         X = numpy.array(X, dtype=numpy.float32)