"Too many input arguments" for basic operations on transfer functions

Hello,

I have a problem using the Control Model Toolbox that I never had before using Matlab R2019B.

Whenever I try to make some operations on transfer functions, I hace the same "Too many input arguments" problem.

For example :

>> s = tf('s');
>> s

s =
 
  s
 
Continuous-time transfer function.

>> 2*s
Error using  *  (line 80)
Too many input arguments.
 
>> s+1
Error using  +  (line 63)
Too many input arguments.
 
>> s^2

ans =
 
  s^2
 
Continuous-time transfer function.

>> tf(1,[1,1]) * tf(1,[1,2,1])
Error using  *  (line 80)
Too many input arguments.

As anyone ever met this problem ? My research hasn't led to any result.

Thanks

Answer 1

[Léo Bellorget]

Actually, the reason was that I had a function called "conv" in my working directory. Renaming it solved the problem.

Answer 2

[Steven Lord]

Make sure you haven't written your own mtimes.m or times.m file that's taking precedence over the built-in mtimes or times function. [I believe the mtimes method for tf may call times when the inputs are scalar.] What do you see when you run these commands?

which -all mtimes

which -all times

[madhan ravi]

Also for plus and tf

[Léo Bellorget]

Thanks for your answer. Here are the results of the mtimes and times commands :

>> which -all mtimes
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@char\mtimes)                            % char method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@double\mtimes)                          % double method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@int16\mtimes)                           % int16 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@int32\mtimes)                           % int32 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@int64\mtimes)                           % int64 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@int8\mtimes)                            % int8 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@logical\mtimes)                         % logical method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@single\mtimes)                          % single method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@uint16\mtimes)                          % uint16 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@uint32\mtimes)                          % uint32 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@uint64\mtimes)                          % uint64 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@uint8\mtimes)                           % uint8 method
C:\Program Files\MATLAB\R2019b\toolbox\control\ctrlmodels\@InputOutputModel\mtimes.m                 % InputOutputModel method
mtimes is a built-in method                                                                          % connector.internal.LoggerLevel method
C:\Program Files\MATLAB\R2019b\toolbox\shared\controllib\engine\+ltipack\@tfdata\mtimes.m            % ltipack.tfdata method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\timefun\@duration\mtimes.m                             % duration method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\datatypes\calendarDuration\@calendarDuration\mtimes.m  % calendarDuration method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\bigdata\@tall\mtimes.m                                 % tall method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\timeseries\@timeseries\mtimes.m                        % timeseries method
C:\Program Files\MATLAB\R2019b\toolbox\slcoverage\@cvdata\mtimes.m  % cvdata method

>> which -all times
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@char\times)                            % char method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@double\times)                          % double method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@int16\times)                           % int16 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@int32\times)                           % int32 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@int64\times)                           % int64 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@int8\times)                            % int8 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@logical\times)                         % logical method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@single\times)                          % single method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@uint16\times)                          % uint16 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@uint32\times)                          % uint32 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@uint64\times)                          % uint64 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@uint8\times)                           % uint8 method
C:\Program Files\MATLAB\R2019b\toolbox\control\ctrlmodels\@DynamicSystem\times.m                    % DynamicSystem method
times is a built-in method                                                                          % connector.internal.LoggerLevel method
C:\Program Files\MATLAB\R2019b\toolbox\shared\controllib\engine\+ltipack\@tfdata\times.m            % ltipack.tfdata method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\timefun\@duration\times.m                             % duration method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\datatypes\calendarDuration\@calendarDuration\times.m  % calendarDuration method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\datatypes\categorical\@categorical\times.m            % categorical method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\bigdata\@tall\times.m                                 % tall method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\timeseries\@timeseries\times.m                        % timeseries method
% C:\Program Files\MATLAB\R2019b\toolbox\slcoverage\@cvdata\times.m% cvdata method

[Léo Bellorget]

And here is the result of the plus and tf commands :

>> which -all plus
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@char\plus)                            % char method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@double\plus)                          % double method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@int16\plus)                           % int16 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@int32\plus)                           % int32 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@int64\plus)                           % int64 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@int8\plus)                            % int8 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@logical\plus)                         % logical method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@single\plus)                          % single method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@uint16\plus)                          % uint16 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@uint32\plus)                          % uint32 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@uint64\plus)                          % uint64 method
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\ops\@uint8\plus)                           % uint8 method
plus is a built-in method                                                                          % string method
C:\Program Files\MATLAB\R2019b\toolbox\control\ctrlmodels\@InputOutputModel\plus.m                 % InputOutputModel method
plus is a built-in method                                                                          % connector.internal.LoggerLevel method
C:\Program Files\MATLAB\R2019b\toolbox\shared\controllib\engine\+ltipack\@tfdata\plus.m            % ltipack.tfdata method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\strfun\@string\plus.m                                % string method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\timefun\@datetime\plus.m                             % datetime method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\timefun\@duration\plus.m                             % duration method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\datatypes\calendarDuration\@calendarDuration\plus.m  % calendarDuration method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\bigdata\@tall\plus.m                                 % tall method
C:\Program Files\MATLAB\R2019b\toolbox\matlab\timeseries\@timeseries\plus.m                        % timeseries method
C:\Program Files\MATLAB\R2019b\toolbox\slcoverage\@cvdata\plus.m                                   % cvdata method
C:\Program Files\MATLAB\R2019b\toolbox\symbolic\symbolic\@sym\plus.m     % sym method

which -all tf
C:\Program Files\MATLAB\R2019b\toolbox\control\ctrlmodels\@tf\tf.m                     % tf constructor
C:\Program Files\MATLAB\R2019b\toolbox\control\ctrlmodels\@DynamicSystem\tf.m          % DynamicSystem method
C:\Program Files\MATLAB\R2019b\toolbox\shared\controllib\engine\+ltipack\@tfdata\tf.m  % ltipack.tfdata method
C:\Program Files\MATLAB\R2019b\toolbox\ident\ident\@idParametric\tf.m                  % idParametric method
C:\Program Files\MATLAB\R2019b\toolbox\shared\controllib\engine\@StaticModel\tf.m      % StaticModel method