Accessing data dictionary from Simulink model InitFcn callback

I have a Simulink model. I don't want to use variables from the base workspace, since the behavior could then be changed if someone else introduces variables with the same name. So I linked the model to a data dictionary. The problem is, the value of some variables are derived from other variables.

For instance:

in data dictionary: x=2, y = 5

derived parameters: z1 = x + y, z2 = x - y

I implemented the InitFcn callback with assignment for z1 and z2, however the initFcn does not have access to the variables from the data dictionary

Undefined function or variable 'x'. Variable 'x' does not exist.

Is there a way to access the Data Dictionary from a function or a script?

Answer 1

[TAB]

Simulink do not saves data dictionary parameters into base workspace.

To access Data Dictionary parameters you need to use APIs. Use code like below in InitFcn callback

dictObj = Simulink.data.dictionary.open('YourDD.sldd');
secObj = getSection(dictObj, 'YourSection Name');
enObjX = getEntry(secObj, 'x');
enObjY = getEntry(secObj, 'y');
temp_x = getValue(enObjX);
temp_y = getValue(enObjY);

% Your operation. Example: z = temp_x.Value + temp_y.Value;

close(dictObj);

clear dictObj secObj enObjX enObjY temp_x temp_y;

It is better to create a load script (m file) and call in InitFcn instead of writing the code in InitFcn.

[HaMo]

Thanks, I just had to add the following lines of code for it to work:

If there is already an entry called z1 in data dictionary

entry = getEntry(secObj, 'z1');
entry.setValue(temp_x.Value + temp_y.Value);

Otherwise

addEntry(secObj, 'z1', temp_x.Value + temp_y.Value)