[Octave-bug-tracker] [bug #49295] tf object gives wrong results with impulse (and initial)

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?49295>

                 Summary: tf object gives wrong results with impulse (and
initial)
                 Project: GNU Octave
            Submitted by: None
            Submitted on: Sat 08 Oct 2016 12:53:42 AM UTC
                Category: Octave Forge Package
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: Juan C. Cockburn
        Originator Email: address@hidden
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 4.0.2
        Operating System: GNU/Linux

    _______________________________________________________

Details:


% Control package version 3.0.0
% Impulse response test
  t=linspace(0,T,150); % time vector
% create transfer function
  H=tf(1,[1 1]);
% impulse response - analytic expression
  ht=exp(-t)';
% impulse response - numerical
  ht_num=impulse(H,t);
% difference (should be close to eps) but is not !
 err=ht - ht_num;

%% Then repeat but with state-space object
  Hss=ss((tf(1,[1 1])); % create state-space object
% numerical simulation
  ht_num_ss=impulse(Hss,t);
% difference is as expected
  err_ss=ht - ht_num_ss






    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?49295>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.gnu.org/