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Initialize Matrix Using a Nontunable Structure Parameter

Open Model

This example shows how to use a nontunable structure parameter input to output a matrix in a MATLAB Function block. Open the model, matrix_struct_param_model.

In this example, the model uses a pre-load callback that defines a structure, p, in the base workspace. p has two fields, rows and cols. To view the callback, in the Modeling tab, click Model Settings > Model Properties. In the Callbacks tab, click PreLoadFcn.

View the MATLAB Function Block and Variable Properties

Open the MATLAB Function block. The function uses the block input u and the parameter p to define the matrix output y. The function adds the value of the input variable u to each element of an empty matrix with a size determined by the fields of p. The function uses this MATLAB® code:

function y = fcn(u, p)
y = zeros(p.rows,p.cols) + u;

In the Function tab, click Edit Data to open the Property Inspector and the Symbols pane. p is a parameter variable, and therefore does not have a port. See Use Data in Multiple MATLAB Function Blocks by Defining Parameter Variables. Instead, it uses the values from the base workspace variable p defined in the callback.

Click p to view the properties in the Property Inspector. The Scope property of p is Parameter and the Tunable property is cleared.

Run the Model

Run the model. The MATLAB Function block outputs a 2-by-3 matrix with 99 in each element. You can adjust the size of the matrix by adjusting the fields of p in the callback.

See Also

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