anchor.diff:                  let step = 
                        LinearAlgebra.SolveLinearSystem (LinearAlgebra.Cholesky hessian) (Matrix.mulV (Matrix.transpose jacobian') residualVector')     
                   ///
  -                let newParamGuess = Vector.sub currentParamGuess step
  +                let newParamGuess = currentParamGuess - step
                   /// 
                   newValueRSS <- getRSS model xData yData newParamGuess
                   ///
  
positive.code:             let paramCount = solverOptions.InitialParamGuess.Length
              let dataPointCount = xData.Length
              let currentParamGuess = Vector.ofArray solverOptions.InitialParamGuess
              let newParamGuess     = Vector.zero paramCount
              let jacobian       = Matrix.create dataPointCount paramCount 0.
              let residualVector = Vector.create dataPointCount 0.
              ///
              currentValueRSS <- getRSS model xData yData currentParamGuess
              while (anotherIteration = true) do 
  
                  /// 
                  let jacobian' = updateJacobianInplace model dataPointCount xData currentParamGuess jacobian            
                  ///
  
negative.code:                 /// 
                  anotherIteration <- shouldTerminate currentValueRSS newValueRSS paramsAtIteration.Count currentParamGuess newParamGuess solverOptions
                  /// 
                  Vector.inplace_mapi (fun i _ -> newParamGuess.[i]) currentParamGuess
                  /// 
                  currentValueRSS <- newValueRSS
              paramsAtIteration
  