Mu Analysis and Synthesis Toolbox

Convert single-input/single-output (SISO) transfer functions to SYSTEM matrices

Syntax

• sys = nd2sys(num,den,gain) 
  sys = zp2sy(zeros,poles,gain)
  

Description
nd2sys converts a numerator/denominator (num,den) SISO transfer function into a SYSTEM matrix, sys. This function uses the MATLAB command tf2ss for the conversion. zp2sys converts zeros and poles of a SISO transfer function into a SYSTEM matrix, sys. This function uses the MATLAB command zp2ss to do the conversion. An optional argument gain can be supplied to scale the transfer function. The default value of gain is 1. The output SYSTEM matrix, sys, is balanced with a call to the µ-Tools command sysbal prior to being return if the real parts of the poles are all less than zero.

Examples
Convert the single-input/single-output transfer function sys1 into a SYSTEM matrix.

• sys = nd2sys([4 5 1],[7 3 6 2 8]); 
  minfo(sys)
  system:4 states1 outputs1 inputs
  see(sys)
  see (sys)
  A matrix
  
  B matrix
      1
      0
      0
      0
  
  C matrix
  0    0.5714    0.7143    0.1429
  
  D matrix
      0
  

Algorithm
nd2sys and zp2sys realize the transfer functions using the MATLAB commands tf2ss and zp2ss.

See Also
pss2sys, pck, tf2ss

ncfsyn, cf2sys, emargin

negangle