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Selecting the Data Format for Exported Simulation Data

Data Format for Block-Based Exported Data

You can use the Scope, To File, and To Workspace blocks to export simulation data. Each of these blocks has a parameter that you use to specify the data format.

Data Format for Model-Based Exported Data

The data format for model-based exporting of simulation data specifies how Simulink stores the exported data.

Simulink uses different data formats, depending on the kind of data that you export. For details, see:

Signal Logging Format

Use the Dataset or ModelDataLogs format for signal logging data. Select the format using the Configuration Parameters > Data Import/Export > Signal logging format parameter.

For details, see Specifying the Signal Logging Data Format.

Logged Data Store Format

When you log data store data, Simulink uses a Simulink.SimulationData.Dataset object.

For details, see Accessing Data Store Logging Data.

State and Output Data Format

For exported state, final state, and output data, use one of the following formats:

Array

If you select this Array option, Simulink saves the states and outputs of a model in a state and output array, respectively.

The state matrix has the name specified in the Save to workspace area (for example, xout). Each row of the state matrix corresponds to a time sample of the states of a model. Each column corresponds to an element of a state. For example, suppose that your model has two continuous states, each of which is a two-element vector. Then the first two elements of each row of the state matrix contains a time sample of the first state vector. The last two elements of each row contain a time sample of the second state vector.

The model output matrix has the name specified in the Save to workspace area (for example, yout). Each column corresponds to a model output port, and each row to the outputs at a specific time.

Structure with Time

If you select this format, Simulink saves the model states and outputs in structures that have their names specified in the Save to workspace area. By default, the structures are xout for states and yout for output.

The structure used to save outputs has two top-level fields:

Each substructure has four fields:

The following example shows the structure-with-time format for a nonreferenced model.

>> xout.signals(1)

ans = 

               values: [296206x1 double]
           dimensions: 1
                label: 'CSTATE'
            blockName: 'vdp/x1'
    inReferencedModel: 0
 

The structure used to save states has a similar organization. The states structure has two top-level fields:

Each signals structure has four fields: values, dimensions, label, and blockName. The values field contains time samples of a state of the block specified by the blockName field. The label field for built-in blocks indicates the type of state: either CSTATE (continuous state) or DSTATE (discrete state). For S-Function blocks, the label contains whatever name is assigned to the state by the S-Function block.

The time samples of a state are stored in the values field as a matrix of values. Each row corresponds to a time sample. Each element of a row corresponds to an element of the state. If the state is a matrix, the matrix is stored in the values array in column-major order. For example, suppose that the model includes a 2-by-2 matrix state and that 51 samples of the state are logged during a simulation run.

The values field for this state would contain a 51-by-4 matrix. Each row corresponds to a time sample of the state, and the first two elements of each row correspond to the first column of the sample. The last two elements correspond to the second column of the sample.

Structure

This format is the same as for Structure with time output format, except that Simulink does not store simulation times in the time field of the saved structure.

Per-Port Structure

This format consists of a separate structure-with-time or structure-without-time for each output port. Each output data structure has only one signals field. To specify this option, enter the names of the structures in the Output text field as a comma-separated list, out1, out2,..., outN, where out1 is the data for your model's first port, out2 for the second input port, and so on.

  


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