Rules for Using Complex Data in C Charts

Complex data is data whose value is a complex number. For example, in a Stateflow^® chart in Simulink^® model, an input signal with the value 3 + 5i is complex. See Complex Data in Stateflow Charts.

These rules apply when you use complex data in Stateflow charts that use C as the action language.

 Do not use complex number notation in actions

C charts do not support complex number notation (a + bi), where a and b are real numbers. Therefore, you cannot use complex number notation in state actions, transition conditions and actions, or any statements in C charts.

To define a complex number, use the complex operator as described in Notation for Complex Data.

 Do not perform math function operations on complex data in C charts

Math operations such as sin, cos, min, max, and abs do not work with complex data in C charts. However, you can use MATLAB^® functions for these operations.

For more information, see Perform Math Function Operations with a MATLAB Function.

 Mix complex and real operands only for addition, subtraction, and multiplication

If you mix operands for any other math operations in C charts, an error appears when you try to simulate your model.

To mix complex and real operands for division, you can use a MATLAB function as described in Perform Complex Division with a MATLAB Function.

Tip

Another way to mix operands for division is to use the complex, real, and imag operators in C charts.

Suppose that you want to calculate y = x1/x2, where x1 is complex and x2 is real. You can rewrite this calculation as:

y = complex(real(x1)/x2, imag(x1)/x2)

For more information, see Access Real and Imaginary Parts of a Complex Number.

 Do not define complex data with constant scope

If you define complex data with Constant scope, an error appears when you try to simulate your model.

 Do not define complex data with ml, struct, or boolean base type

If you define complex data with ml, struct, or boolean base type, an error appears when you try to simulate your model.

 Use only real values to set initial values of complex data

When you define the initial value for data that is complex, use only a real value. See Additional Properties for instructions on setting an initial value in the Data properties dialog box.

 Do not enter minimum or maximum values for complex data

In the Data properties dialog box, do not enter any values in the Minimum or Maximum field when you define complex data. If you enter a value in either field, an error message appears when you try to simulate your model.

 Assign complex values only to data of complex type

If you assign complex values to real data types, an error appears when you try to simulate your model.

Note

You can assign both real and complex values to complex data types.

 Do not pass real values to function inputs of complex type

This restriction applies to the following types of chart functions:

• Graphical functions

• Truth table functions

• MATLAB functions

• Simulink functions

If your C chart passes real values to function inputs of complex type, an error appears when you try to simulate your model.

 Do not use complex data with temporal logic operators

You cannot use complex data as an argument for temporal logic operators, because you cannot define time as a complex number.

Related Topics

• Complex Data in Stateflow Charts
• Operations for Complex Data in Stateflow
• Best Practices for Using Complex Data in C Charts