/// <summary>
 /// Returns the variable in the index [index] of the vtkLookupTable [arr]
 /// </summary>
 /// <param name="arr"></param>          
 /// <param name="index"></param>
 public static long lindex(vtkLookupTable arr, double index)
 {
     return (long)arr.GetIndex(index);
 }
 /// <summary>
 /// Returns the variable in the index [index] of the vtkLookupTable [arr]
 /// </summary>
 /// <param name="arr"></param>
 /// <param name="index"></param>
 public static long lindex(vtkLookupTable arr, double index)
 {
     return(arr.GetIndex(index));
 }