MATLAB: Are Simulink.Signal objects’ Max and Min not enforced in the generated code

simulink

I have a model where several signals are associated with a "Simulink.Signal" object. These objects have a specified "Max" and "Min" parameter. However, I do not see these limits enforced in the generated code. Why is it that these limits appear to be arbitrary?

Best Answer

Currently, the "Max" and "Min" properties of "Simulink.Signal" objects have no effect on the generated code. These parameters are meant for simulation range checking only, as described in the following documentation:

https://www.mathworks.com/help/releases/R2017b/simulink/slref/signal.html#property_d119e294167

https://www.mathworks.com/help/releases/R2017b/simulink/slref/signal.html#property_d119e294244

With the "Simulation range checking" diagnostic set to "warning" or "error", Simulink will notify you when the selected signal exceeds the range set by the Minimum and Maximum parameters of the corresponding "Simulink.Signal" object.

In order to conduct a form of range checking in the generated code, one approach is to include a "Saturation" block. This block will effectively limit the signal between the specified saturation values.

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MATLAB: Do I get an error when setting the LineStyle property for multiple lines in MATLAB 7.4 (R2007a)

The "LineStyle" property for a line object only accepts values of '-', '--', ':', '-.' or 'none'. You can use the "Marker" property to separately set marker symbols. To illustrate, here is an example:

h = plot(rand(10,6))
set(h, {'LineStyle'}, {'-';'--';'--';':';':';':'})
set(h, {'Marker'}, { 'none'; 'o'; 'x'; 'none'; 'none'; 'none'; })

For further help with Line properties in R2007a, refer to the corresponding documentation:

https://www.mathworks.com/help/releases/R2007a/techdoc/index.html?/help/releases/R2007a/techdoc/ref/line_props.html

For your reference, here is a link to the corresponding documentation for a more recent MATLAB version, e.g. R2018b:

https://www.mathworks.com/help/releases/R2018b/matlab/ref/matlab.graphics.chart.primitive.line-properties.html

MATLAB: ‘Not convertible to floating-point’ error when using min() with symbolic variables

The reason of the error is that the input arguments to "min" are not "convertible to floating-point numbers" as "xx" is a symbolic variable. To avoid the error, one could wrap the call to "min" in another symbolic function such that "xx" is conceivably reduced to a floating number. Here is the code that does that:

xx = sym('xx','real') ;
symmin = @(x,y)feval(symengine,'min',x,y);
LambdaCC = symfun(sqrt(1-2*symmin(xx,1/2)), xx);

Also, the link below might be helpful as well:

https://stackoverflow.com/questions/29527592/matlab-using-a-minimum-function-within-symsum

Best Answer

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MATLAB: Do I get an error when setting the LineStyle property for multiple lines in MATLAB 7.4 (R2007a)

MATLAB: ‘Not convertible to floating-point’ error when using min() with symbolic variables

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