Fitting real world data using the fractional order LTI model K/(tau*s^alpha+1)*exp(-Ls). The parameters for fitting are [K,tau,alpha,L]. The code is to automatically sweep the orders with a user specified step size. Error is uated by IAE(integral absolute error), ITAE, or ISE. User can the method for computing the fractional order model response the following options: NILT, FOTF, Noninteger, etc.-Fitting real world data using the fractional order LTI model K/(tau*s^alpha+1)*exp(-Ls). The parameters for fitting are [K,tau,alpha,L]. The code is to automatically sweep the orders with a user specified step size. Error is　uated by IAE(integral absolute error), ITAE, or ISE. User can　the method for computing the fractional order model response　the following options: NILT, FOTF, Noninteger, etc.