Check for missing argument or incorrect argument data type in call to function 'abs'.

I'm building code for getting IAE and ITAE values from a controller project.

Using a function already tested by me in other programs it returns this error message:

Check for missing argument or incorrect argument data type in call to function 'abs'.

The part of the code that is giving a problem is below:

res = sim('RTS.slx');

erroa= abs(1-res.control);
erroat = abs(dt *(1-res.control));
IAE= trapz(res.tempo, erroa);
ITAE= trapz(res.tempo, erroat);

Answer 1

[Paul]

I doubt that res.control is a numeric array. Depending what how the signal "control" is formed in the simulation RTS, you'll probably need to use addittional qualfiers to get to the actual data in res.control. For example, if control is a timeseries output from a To Workspace block, you'd need

erroa = abs(1 - res.control.Data)

[Lucas Antonelo]

Well, the database refers to the output of an RST controller, making the change you suggested, it returned the following message:

Error using trapz (line 66)

Point spacing must be a scalar specifying uniform spacing or a vector of x-coordinates for each data point.

Error in Trecho2 (line 56)

IAE= trapz(res.tempo, erroa);

[Paul]

Now there is the same issue with res.tempo. You need additional qualification to get to the data in res.tempo that you are trying to access.

[Lucas Antonelo]

But do I use .data? When I run the code it returns:

Error using Trecho2 (line 56)
Dot indexing is not supported for variables of this type..

[Paul]

More information needed. Type these two lines in the command window and copy the results here

res.control
res.tempo

[Lucas Antonelo]

res.tempo
  timeseries

  Common Properties:
            Name: ''
            Time: [84x1 double]
        TimeInfo: [1x1 tsdata.timemetadata]
            Data: [84x3000 double]
        DataInfo: [1x1 tsdata.datametadata]

  More properties, Methods


ans =

         0
    0.2500
    0.5000
    0.7500
    1.0000
    1.2500
    1.5000
    1.7500
    2.0000
    2.2500
    2.5000
    2.7500
    3.0000
    3.2500
    3.5000
    3.7500
    4.0000
    4.2500
    4.5000
    4.7500
    5.0000
    5.2500
    5.5000
    5.7500
    6.0000
    6.2500
    6.5000
    6.7500
    7.0000
    7.2500
    7.5000
    7.7500
    8.0000
    8.2500
    8.5000
    8.7500
    9.0000
    9.2500
    9.5000
    9.7500
   10.0000
   
  >> res.control
  timeseries

  Common Properties:
            Name: ''
            Time: [84x1 double]
        TimeInfo: [1x1 tsdata.timemetadata]
            Data: [84x3000 double]
        DataInfo: [1x1 tsdata.datametadata]

  More properties, Methods

>> 

[Image Analyst]

It seem you can't subtract a time series from 1. Try to convert it to a double somehow. Maybe you meant (1-res.control.Time) or something?

[Lucas Antonelo]

@Image Analyst , the result:

Error using Trecho2 (line 55)
Dot indexing is not supported for variables of this type.

[Paul]

res.tempo is a timeseries as is res.control.

res.tempo.Time;  % acceses the time vector
res.tempo.Data;  % accesses the data values

In both cases, the Data is an 84 x 3000 array, one row per time point. It's likely, but not guaranteed, that res.tempo.Time and res.control.Time are equal to each other. I think you could do

erroa = 1 - res.control.Data;

but then erroa will be a timeseries that you can't input directly to trapz.

Maybe you you want to do something like this?

erroa = abs(1 - res.control.Data); % 84 x 3000 array
ITAE = trapz(res.control.Time,erroa) ; % should be a 1 x 3000 array, integrating each colum wrt time

[Lucas Antonelo]

The same error mensage returns

[Paul]

Hmm. Should work just fine:

res.control = timeseries(rand(84,3000),0:83);
res.control

  timeseries

  Common Properties:
            Name: 'unnamed'
            Time: [84x1 double]
        TimeInfo: tsdata.timemetadata
            Data: [84x3000 double]
        DataInfo: tsdata.datametadata

erroa = abs(1 - res.control.Data);
iae = trapz(res.control.Time,erroa);
size(iae)

ans = 1×2

1 3000

Of course, res is just a regular structure here, not a Simulink.SimulationOutput object, but that shouldn't matter.

Do you see this after the which() command?

which trapz -all

/MATLAB/toolbox/matlab/datafun/trapz.m
/MATLAB/toolbox/parallel/gpu/@gpuArray/trapz.m            % Shadowed gpuArray method
/MATLAB/toolbox/parallel/parallel/@codistributed/trapz.m  % Shadowed codistributed method

[Image Analyst]

Try operating on one column of data at a time

columnNumber = 15; % whatever...
erroa = 1 - res.control.Data(:, columnNumber);

Answer 2

[Image Analyst]

res does not have a field, property, or method called control. What does this show:

res = sim('RTS.slx')  % Don't use a semicolon
fieldnames(res)
properties(res)
methods(res)
v = res.control
whos v

Dont' use semicolons. If any throw errors, just comment them out and tell us what the rest display in the command window.