diff --git a/LibSVMsharp/Core/svm_node.cs b/LibSVMsharp/Core/svm_node.cs
index f237531..43e5e2d 100644
--- a/LibSVMsharp/Core/svm_node.cs
+++ b/LibSVMsharp/Core/svm_node.cs
@@ -1,16 +1,11 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Runtime.InteropServices;
-using System.Text;
-using System.Threading.Tasks;
+using System.Runtime.InteropServices;
 
 namespace LibSVMsharp.Core
 {
     [StructLayout(LayoutKind.Sequential)]
     public struct svm_node
     {
-        internal int index;
-        internal double value;
+        public int index;
+        public double value;
     }
 }
diff --git a/LibSVMsharp/Extensions/SVMProblemExtensions.cs b/LibSVMsharp/Extensions/SVMProblemExtensions.cs
index 2969e78..68ec6af 100644
--- a/LibSVMsharp/Extensions/SVMProblemExtensions.cs
+++ b/LibSVMsharp/Extensions/SVMProblemExtensions.cs
@@ -2,8 +2,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace LibSVMsharp.Extensions
 {
@@ -82,7 +80,7 @@ public static double[] PredictValues(this SVMProblem problem, SVMModel model, ou
             double[] target = problem.X.Select(x =>
             {
                 double[] estimations;
-                double y = x.PredictProbability(ptr_model, out estimations);
+                double y = x.PredictValues(ptr_model, out estimations);
                 temp.Add(estimations);
                 return y;
             }).ToArray();
diff --git a/LibSVMsharp/SVMNode.cs b/LibSVMsharp/SVMNode.cs
index b73f398..00b1ddb 100644
--- a/LibSVMsharp/SVMNode.cs
+++ b/LibSVMsharp/SVMNode.cs
@@ -1,9 +1,7 @@
 using LibSVMsharp.Core;
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Runtime.InteropServices;
-using System.Text;
 
 namespace LibSVMsharp
 {
@@ -51,7 +49,7 @@ public static SVMNode[] Convert(IntPtr ptr)
             {
                 svm_node node = (svm_node)Marshal.PtrToStructure(i_ptr_nodes, typeof(svm_node));
                 i_ptr_nodes = IntPtr.Add(i_ptr_nodes, Marshal.SizeOf(typeof(svm_node)));
-                if (node.index > 0)
+                if (node.index >= 0)
                 {
                     nodes.Add(new SVMNode(node.index, node.value));
                 }