diff --git a/src/DotNetBridge/transforms/VariableColumnTransform.cs b/src/DotNetBridge/transforms/VariableColumnTransform.cs
index ea9ecafb..9ee1ebd7 100644
--- a/src/DotNetBridge/transforms/VariableColumnTransform.cs
+++ b/src/DotNetBridge/transforms/VariableColumnTransform.cs
@@ -247,6 +247,9 @@ public override bool IsColumnActive(DataViewSchema.Column column)
                 return _active[column.Index];
             }
 
+            private static readonly FuncInstanceMethodInfo1<Cursor, DataViewRow, Delegate> _makeVarLengthVectorGetterMethodInfo
+                = FuncInstanceMethodInfo1<Cursor, DataViewRow, Delegate>.Create(target => target.MakeVarLengthVectorGetter<int>);
+
             private Delegate MakeVarLengthVectorGetter<T>(DataViewRow input)
             {
                 var srcGetters = new ValueGetter<T>[_bindings.vectorToInputMap.Count];
@@ -304,7 +307,7 @@ public override ValueGetter<TValue> GetGetter<TValue>(DataViewSchema.Column colu
                 if (column.Index == _bindings.outputColumn)
                 {
                     VectorDataViewType columnType = column.Type as VectorDataViewType;
-                    Delegate getter = Utils.MarshalInvoke(MakeVarLengthVectorGetter<int>, columnType.ItemType.RawType, _cursor);
+                    Delegate getter = Utils.MarshalInvoke(_makeVarLengthVectorGetterMethodInfo, this, columnType.ItemType.RawType, _cursor);
                     return getter as ValueGetter<TValue>;
                 }
                 else
diff --git a/src/python/nimbusml/internal/entrypoints/_calibratortrainer_fixedplattcalibrator.py b/src/python/nimbusml/internal/entrypoints/_calibratortrainer_fixedplattcalibrator.py
index 35e80514..8f1904cb 100644
--- a/src/python/nimbusml/internal/entrypoints/_calibratortrainer_fixedplattcalibrator.py
+++ b/src/python/nimbusml/internal/entrypoints/_calibratortrainer_fixedplattcalibrator.py
@@ -10,16 +10,16 @@
 
 
 def fixed_platt_calibrator(
-        slope=1.0,
+        slope=-1.0,
         offset=0.0,
         **params):
     """
     **Description**
         None
 
-    :param slope: The slope parameter of f(x) = 1 / (1 + exp(-slope *
+    :param slope: The slope parameter of f(x) = 1 / (1 + exp(slope *
         x + offset) (settings).
-    :param offset: The offset parameter of f(x) = 1 / (1 + exp(-slope
+    :param offset: The offset parameter of f(x) = 1 / (1 + exp(slope
         * x + offset) (settings).
     """
 
diff --git a/src/python/nimbusml/internal/entrypoints/models_fixedplattcalibrator.py b/src/python/nimbusml/internal/entrypoints/models_fixedplattcalibrator.py
index f5665675..4876c6ff 100644
--- a/src/python/nimbusml/internal/entrypoints/models_fixedplattcalibrator.py
+++ b/src/python/nimbusml/internal/entrypoints/models_fixedplattcalibrator.py
@@ -13,7 +13,7 @@ def models_fixedplattcalibrator(
         data,
         uncalibrated_predictor_model,
         predictor_model=None,
-        slope=1.0,
+        slope=-1.0,
         offset=0.0,
         max_rows=1000000000,
         **params):
@@ -23,12 +23,12 @@ def models_fixedplattcalibrator(
         model
 
     :param slope: The slope parameter of the calibration function 1 /
-        (1 + exp(-slope * x + offset) (inputs).
+        (1 + exp(slope * x + offset) (inputs).
     :param data: Input dataset (inputs).
     :param uncalibrated_predictor_model: The predictor to calibrate
         (inputs).
     :param offset: The offset parameter of the calibration function 1
-        / (1 + exp(-slope * x + offset) (inputs).
+        / (1 + exp(slope * x + offset) (inputs).
     :param max_rows: The maximum number of examples to train the
         calibrator on (inputs).
     :param predictor_model: The trained model (outputs).
diff --git a/src/python/tools/manifest.json b/src/python/tools/manifest.json
index eb019968..fd7f7950 100644
--- a/src/python/tools/manifest.json
+++ b/src/python/tools/manifest.json
@@ -1731,14 +1731,14 @@
         {
           "Name": "Slope",
           "Type": "Float",
-          "Desc": "The slope parameter of the calibration function 1 / (1 + exp(-slope * x + offset)",
+          "Desc": "The slope parameter of the calibration function 1 / (1 + exp(slope * x + offset)",
           "Aliases": [
             "slope"
           ],
           "Required": false,
           "SortOrder": 1.0,
           "IsNullable": false,
-          "Default": 1.0
+          "Default": -1.0
         },
         {
           "Name": "Data",
@@ -1762,7 +1762,7 @@
         {
           "Name": "Offset",
           "Type": "Float",
-          "Desc": "The offset parameter of the calibration function 1 / (1 + exp(-slope * x + offset)",
+          "Desc": "The offset parameter of the calibration function 1 / (1 + exp(slope * x + offset)",
           "Aliases": [
             "offset"
           ],
@@ -25355,19 +25355,19 @@
             {
               "Name": "Slope",
               "Type": "Float",
-              "Desc": "The slope parameter of f(x) = 1 / (1 + exp(-slope * x + offset)",
+              "Desc": "The slope parameter of f(x) = 1 / (1 + exp(slope * x + offset)",
               "Aliases": [
                 "a"
               ],
               "Required": false,
               "SortOrder": 150.0,
               "IsNullable": false,
-              "Default": 1.0
+              "Default": -1.0
             },
             {
               "Name": "Offset",
               "Type": "Float",
-              "Desc": "The offset parameter of f(x) = 1 / (1 + exp(-slope * x + offset)",
+              "Desc": "The offset parameter of f(x) = 1 / (1 + exp(slope * x + offset)",
               "Aliases": [
                 "b"
               ],