I keep getting the following error message: Execution of script Dummy as a function is not supported: C:\Musical​SoundAnaly​sis\Analys​is\Dummy.m

the function is

functio [lent,delt,tmax,T]=Dummy(nP,frq,fs)
T = nP*(1/frq);   % max argument of sawtooth s
h=1/fs;    % sampling interval s
fNy=fs/2;   % Nyquist freq
t = 0:1/fs:T-1/fs;  % time grid for saw
tmax=max(t);
delt=t(2)-t(1);   % sampling interval s
lent=length(t);
disp(['for nP = ' num2str(nP) ' length of t = ' num2str(lent)])
disp(['delt = ' num2str(delt) ' s,  max t = ' num2str(tmax)])

and the caller is

frq=65.4064;   % Hzn
nP=30;
fs = 1000;   % sampling frequency  Hz
[lent_p,delt_p,tmax_p,T_p]=Dummy(nP,frq,fs);

The response is

Execution of script Dummy as a function is not supported: C:\MusicalSoundAnalysis\Analysis\Dummy.m

Am I doing something stupid?

>> ver
-----------------------------------------------------------------------------------------------------
MATLAB Version: 9.14.0.2206163 (R2023a)
MATLAB License Number: 521792
Operating System: Microsoft Windows 11 Pro Version 10.0 (Build 26100)
Java Version: Java 1.8.0_202-b08 with Oracle Corporation Java HotSpot(TM) 64-Bit Server VM mixed mode
-----------------------------------------------------------------------------------------------------
MATLAB                                                Version 9.14        (R2023a)
Simulink                                              Version 10.7        (R2023a)
Control System Toolbox                                Version 10.13       (R2023a)
DSP System Toolbox                                    Version 9.16        (R2023a)
Signal Processing Toolbox                             Version 9.2         (R2023a)
Symbolic Math Toolbox                                 Version 9.3         (R2023a)
System Identification Toolbox                         Version 10.1        (R2023a)
>> 

[Stephen23]

functio [lent,delt,tmax,T]=Dummy(nP,frq,fs)
      ^^ check the spelling

[David Koenig]

yes! thanks!

Answer 1

[dpb]

The function keyword is missing the final "n" so it won't be recognized; hence, MATLAB thinks Dummy.m is a script and not a function; hence the error when trying to pass arguments to it.

Try

function [lent,delt,tmax,T]=Dummy(nP,frq,fs)
  T = nP*(1/frq);   % max argument of sawtooth s
  h=1/fs;    % sampling interval s
  fNy=fs/2;   % Nyquist freq
  t = 0:1/fs:T-1/fs;  % time grid for saw
  tmax=max(t);
  delt=t(2)-t(1);   % sampling interval s
  lent=length(t);
  disp(['for nP = ' num2str(nP) ' length of t = ' num2str(lent)])
  disp(['delt = ' num2str(delt) ' s,  max t = ' num2str(tmax)])
end

frq=65.4064;   % Hzn
nP=30;
fs = 1000;   % sampling frequency  Hz
[lent_p,delt_p,tmax_p,T_p]=Dummy(nP,frq,fs);

for nP = 30 length of t = 458
delt = 0.001 s,  max t = 0.457

Also Nota Bene the use of the end keyword. While not absolutely mandatory in a standalone m-file, it is certainly best practice to use it and would be needed here to separate it from the calling code.

[dpb]

function [lent,delt,tmax,T]=Dummy(nP,frq,fs)
  T = nP*(1/frq);                   % max argument of sawtooth s
  delt=1/fs;                        % sampling interval s
  fNy=fs/2;                         % Nyquist freq
  t=0:delt:T-1/fs;                  % time grid for saw
  tmax=t(end);                      % max is last element, cheaper than max()
  lent=numel(t);                    % length() is dangerous, avoid 
  fprintf('For nP = %d length of t = %d\n',nP,lent)
  fprintf('delt = %gs,  max t = %gs\n',delt,tmax)
end

frq=65.4064;   % Hzn
nP=30;
fs = 1000;   % sampling frequency  Hz
[lent_p,delt_p,tmax_p,T_p]=Dummy(nP,frq,fs);

For nP = 30 length of t = 458
delt = 0.001s,  max t = 0.457s

[David Koenig]

Thanks! my bad!

[dpb]

Can be easy to overlook the obvious trivial detail thinking it has to be something deeper...outside eyes help.

Might go ahead and Accept an answer to show it has been solved to others if no other reason...