To main content

Vector Fitting

mtrxfit shows one way of applying Vector Fitting to identification of multi terminal systems. It has options for creating ATP branch cards as well as a crude passivity enforcement procedure.

This package shows one way of applying Vector Fitting to multi-terminal problems. The main program features options for automatic generation of starting poles and enforcement of symmetry. The resulting model is given in two forms:

  • Sum of pole-residue terms
  • State space model (A,B,C,D)


File Purpose
spavectfit.m Sparse version of vectfit.m, called from mtrxvectfit.m
mainfit.m Main program
 mtrxvectfit.m Utility routine, called from mainfit.m
passive.m  Utility routine for passivity enforcement, called from mainfit.m
netgen.m Utility routine for generation electrical network compatible with ATP-EMTP, called from mainfit.m
user_manual.pdf A tutorial on how to apply the package
tutorial.m Example case described in user_manual.pdf
 circuit.atp ATP-EMTP data fil which imports the electrical network generated in example tutorial.m
mtrxfit.pdf IEEE paper describing the mathematics behind the package


  1. The call parameters for spavectfit.m are different from those of vectfit.m.
  2. In addition, spavectfit.m allows to use individual weighting for all elements in vector.
  3. The convergence properties of spavectfit.m are similar to those of version 1.0 of vectfit.