SharePoint Rating Enable and Disable programmatically

The following code snippet can be used to SharePoint rating enable and disable programmatically.

 private static void EnableRatingSetting(SPList list)
        {
            SPFieldCollection allfields = list.Fields;
            SPFieldCollection availFields = list.ParentWeb.AvailableFields;
            if (!allfields.Contains(FieldId.AverageRatings))
            {
                SPField field = availFields[FieldId.AverageRatings];
                list.Fields.AddFieldAsXml(field.SchemaXmlWithResourceTokens, true, SPAddFieldOptions.AddFieldToDefaultView | SPAddFieldOptions.AddFieldInternalNameHint | SPAddFieldOptions.AddToAllContentTypes);
            }
            if (!allfields.Contains(FieldId.RatingsCount) && availFields.Contains(FieldId.RatingsCount))
            {
                SPField field2 = availFields[FieldId.RatingsCount];
                list.Fields.AddFieldAsXml(field2.SchemaXmlWithResourceTokens, false, SPAddFieldOptions.AddFieldInternalNameHint | SPAddFieldOptions.AddToAllContentTypes);
            }
            list.Update();
        }

   private static void DisableRatingSetting(SPList list)
        {
            SPField field1 = GetField(FieldId.AverageRatings, list.Fields);
            if (field1 != null)
            {
                list.Fields.Delete(field1.InternalName);
            }
            SPField field2 = GetField(FieldId.RatingsCount, list.Fields);
            if (field2 != null)
            {
                list.Fields.Delete(field2.InternalName);
            }
            list.Update();
        }
        private static SPField GetField(Guid id, SPFieldCollection fieldColl)
        {
            return fieldColl[id];
        }