???Error using feval Undefined function 'pfpower' for input arguments of type 'double'.???

Hi everybody

I was trying to understand previous answers to similar questions as mine indcated in Question subject above, but I didn't get it.

I'm using Matlab R2012a and I'm trying to run the function below from Hadi Saadat textbook, but the first error that I get is:

Error using feval Undefined function 'pfpower' for input arguments of type 'double'.

Could you please give me any hint ? it's because the function was developed in another Matlab version.

Thanks in advance for your help

<<function-nbsp--nbsp-Cctime-Pm--nbsp-E--nbsp-V--nbsp-X1--nbsp-X2--nbsp-X3--nbsp-H--nbsp-f--n-nbsp--nbsp-Pe1max-nbsp---nbsp-E-V-X1--nbsp-Pe2max-E-V-X2--nbsp-Pe3max-E-V-X3--n-nbsp--nbsp-d0-nbsp--asin-Pm-Pe1max---n-nbsp--nbsp-dmax-nbsp---nbsp-pi-asin-Pm-Pe3max---n-nbsp--nbsp-cosdc-nbsp---nbsp--Pm--dmax-d0--Pe3max-cos-dmax--Pe2max-cos-d0----Pe3max-Pe2max---n-nbsp--nbsp--nbsp--nbsp-if-nbsp-abs-cosdc--nbsp--gt--nbsp-1-n-nbsp--nbsp--nbsp--nbsp-fprintf--No-nbsp-critical-nbsp-clearing-nbsp-angle-nbsp-could-nbsp-be-nbsp-found---n---n-nbsp--nbsp--nbsp--nbsp-fprintf--System-nbsp-can-nbsp-remain-nbsp-stable-nbsp-during-nbsp-this-nbsp-disturbance---n--n---n-nbsp--nbsp--nbsp--nbsp-return-n-nbsp--nbsp--nbsp--nbsp-else--nbsp-end-n-nbsp--nbsp-dc-nbsp---nbsp-acos-cosdc---n-nbsp--nbsp--nbsp--nbsp-if-nbsp-dc-nbsp--gt--nbsp-dmax-n-nbsp--nbsp--nbsp--nbsp-fprintf--No-nbsp-critical-nbsp-clearing-nbsp-angle-nbsp-could-nbsp-be-nbsp-found---n---n-nbsp--nbsp--nbsp--nbsp-fprintf--System-nbsp-can-nbsp-remain-nbsp-stable-nbsp-during-nbsp-this-nbsp-disturbance---n--n---n-nbsp--nbsp--nbsp--nbsp-return-n-nbsp--nbsp--nbsp--nbsp-else--nbsp-end-n-nbsp--nbsp-tf-nbsp---nbsp-0-4--n-nbsp--nbsp-x0-nbsp---nbsp--d0--nbsp-0---n-nbsp--nbsp---t1-xf--nbsp--ode23--pfpower---nbsp-0--nbsp-tf--nbsp-x0--nbsp-0-00001---nbsp--nbsp--nbsp---nbsp-use-nbsp-with-nbsp-MATLAB-nbsp-4-n-nbsp--nbsp-tspan-nbsp---nbsp--0--nbsp-tf---nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp---nbsp-use-nbsp-with-nbsp-MATLAB-nbsp-5-n-nbsp--nbsp-options-nbsp---nbsp-odeset--RelTol---nbsp-0-00001---nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp---nbsp-use-nbsp-with-nbsp-MATLAB-nbsp-5-n-nbsp--nbsp--t1-xf--nbsp--ode23--pfpower---nbsp-tspan--nbsp-x0--nbsp-options---nbsp--nbsp--nbsp--nbsp---nbsp-use-nbsp-with-nbsp-MATLAB-nbsp-5-n-nbsp--nbsp-kk-find-xf---1--nbsp--lt---nbsp-dc---nbsp-k-max-kk---n-nbsp--nbsp-tt-t1-k---n-nbsp--nbsp-while-nbsp-tf-nbsp--lt---nbsp-tt-nbsp---nbsp-tf-nbsp--lt---nbsp-3-6-n-nbsp--nbsp-tf-tf--4--n-nbsp--nbsp--nbsp--nbsp--nbsp-fprintf----nSearching-nbsp-with-nbsp-a-nbsp-final-nbsp-time-nbsp-of-nbsp--3-2f-nbsp-Sec--nbsp---n---nbsp-tf--n-nbsp--nbsp--nbsp--nbsp--nbsp-tol-0-00001-tf-2-5e-5--n-nbsp--nbsp--nbsp--nbsp--nbsp---t1-xf--nbsp--ode23--pfpower---nbsp-0--nbsp-tf--nbsp-x0--nbsp-tol---nbsp--nbsp--nbsp--nbsp--nbsp---nbsp-use-nbsp-with-nbsp-MATLAB-nbsp-4-n-nbsp--nbsp--nbsp--nbsp--nbsp-tspan-nbsp---nbsp--0--nbsp-tf---nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp---nbsp-use-nbsp-with-nbsp-MATLAB-nbsp-5-n-nbsp--nbsp--nbsp--nbsp--nbsp-options-nbsp---nbsp-odeset--RelTol---nbsp-tol---nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp---nbsp-use-nbsp-with-nbsp-MATLAB-nbsp-5-n-nbsp--nbsp--nbsp--nbsp--nbsp--t1-xf--nbsp--ode23--pfpower---nbsp-tspan--nbsp-x0--nbsp-options---nbsp--nbsp---nbsp-use-nbsp-with-nbsp-MATLAB-nbsp-5-n-nbsp--nbsp--nbsp--nbsp--nbsp-kk-find-xf---1--nbsp--lt---nbsp-dc---nbsp-k-max-kk---n-nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp--nbsp-tt--nbsp-t1-k---n-nbsp--nbsp-end-n-nbsp--nbsp--end-n-nbsp--nbsp-tmargin-nbsp---nbsp-t1-k---n-nbsp--nbsp-if-nbsp-tf-nbsp--gt---nbsp-3-6-n-nbsp--nbsp--nbsp--nbsp-fprintf----nA-nbsp-clearing-nbsp-time-nbsp-could-nbsp-not-nbsp-be-nbsp-found-nbsp-up-nbsp-to-nbsp-4-nbsp-sec--nbsp---n--n---n-nbsp--nbsp--nbsp--nbsp-return-n-nbsp--nbsp--nbsp--nbsp-else--nbsp-end-n-nbsp--nbsp-fprintf----nCritical-nbsp-clearing-nbsp-time-nbsp---nbsp--nbsp--4-2f-nbsp-seconds-nbsp---n---nbsp-tmargin--n-nbsp--nbsp-fprintf--Critical-nbsp-clearing-nbsp-angle-nbsp---nbsp--6-2f-nbsp-degrees-nbsp---n--n---nbsp-dc-180-pi.>>

[Claudia]

Sorry, I forgot to include the function..

function  Cctime(Pm, E, V, X1, X2, X3, H, f)
Pe1max = E*V/X1; Pe2max=E*V/X2; Pe3max=E*V/X3;
d0 =asin(Pm/Pe1max);
dmax = pi-asin(Pm/Pe3max);
cosdc = (Pm*(dmax-d0)+Pe3max*cos(dmax)-Pe2max*cos(d0))/(Pe3max-Pe2max);
  if abs(cosdc) > 1
  fprintf('No critical clearing angle could be found.\n')
  fprintf('System can remain stable during this disturbance.\n\n')
  return
  else, end
dc = acos(cosdc);
  if dc > dmax
  fprintf('No critical clearing angle could be found.\n')
  fprintf('System can remain stable during this disturbance.\n\n')
  return
  else, end
tf = 0.4;
x0 = [d0; 0];
%[t1,xf] =ode23('pfpower', 0, tf, x0, 0.00001);   % use with MATLAB 4
tspan = [0, tf];                                  % use with MATLAB 5
options = odeset('RelTol', 0.00001);              % use with MATLAB 5
[t1,xf] =ode23('pfpower', tspan, x0, options);    % use with MATLAB 5
kk=find(xf(:,1) <= dc); k=max(kk);
tt=t1(k);
while tf <= tt & tf <= 3.6
tf=tf+.4;
   fprintf('\nSearching with a final time of %3.2f Sec. \n', tf)
   tol=0.00001+tf*2.5e-5;
   %[t1,xf] =ode23('pfpower', 0, tf, x0, tol);     % use with MATLAB 4
   tspan = [0, tf];                                % use with MATLAB 5
   options = odeset('RelTol', tol);                % use with MATLAB 5
   [t1,xf] =ode23('pfpower', tspan, x0, options);  % use with MATLAB 5
   kk=find(xf(:,1) <= dc); k=max(kk);
      tt= t1(k);
end
%end
tmargin = t1(k);
if tf >= 3.6
  fprintf('\nA clearing time could not be found up to 4 sec. \n\n')
  return
  else, end
fprintf('\nCritical clearing time =  %4.2f seconds \n', tmargin)
fprintf('Critical clearing angle = %6.2f degrees \n\n', dc*180/pi)

[David Sanchez]

could you please insert your function as such? ( use the {}Code option ) It is not easy to follow what's a comment and what's code.

Answer 1

[Yao Li]

It's Ok, if the fucntion is written in the earlier version. Pls. make sure the script (m file) which defines the function is in current folder or has been added to Matlab path.

[Claudia]

Hi, yeah,the script it's in current folder, but I get the same error message

[Yao Li]

Is the script for the function pfpower in current folder? Would u pls. insert the function pfpower as well?

[Claudia]

The function pfpower is now in current folder but three new error messages apears; one of them:

Error in Cctime (line 27) [t1,xf] =ode23('Pfpower', tspan, x0, options); % use with MATLAB 5