Data Format for Logged Simulation Data
Data Format for Block-Based Logged Data
Data Format for Model-Based Logged 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
To control how
Dataset elements are saved, set the Dataset
signal format configuration parameter. The default is
timeseries. For details, see Dataset signal format.
The Dataset signal format parameter applies to signal logging, as
well as output and states data when you set the Format parameter to
Logged Data Store Format
When you log data store data, Simulink uses a
For details, see Accessing Data Store Logging Data.
Time, State, and Output Data Format
For exported time, states, and output data, use one of the following formats:
If you select the Configuration Parameters > Data Import/Export > Output check box, Simulink logs fixed-point data as double. To log fixed-point data, consider using one of these approaches:
Signal logging — For details, see Export Signal Data Using Signal Logging.
In the Simulink Editor, select one or more signals.
Click Log Signals.
To File block
To Workspace block — In the To Workspace Block Parameters dialog box, enable the Log fixed-point data as a fi object parameter.
For information about the format for logged final state data, see Save Block States and Simulation Operating Points.
By default, time, states, and outputs are logged using the
Supports logging multiple data values for a given time step, which can be required for logging data in a For Iterator Subsystem, a While Iterator Subsystem, and Stateflow®.
Does not support logging states inside a function-call subsystem or during rapid accelerator simulations.
Does not support code generation.
Signal logging always uses the
Dataset format. Logging states and
output data using the
Dataset format allows you to post-process
simulation data without writing custom code for different types of logged data. When you
log states and outputs using the
Dataset format, the data also
automatically streams to the Simulation Data Inspector during simulation.
If you select this
Array option, Simulink saves the states and outputs of a model in a state and in an output array,
The state matrix has the name specified in the Configuration Parameters > Data Import/Export pane (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 contain 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 Configuration Parameters > Data Import/Export pane (for example,
yout). Each column corresponds to a
model output port, and each row to the outputs at a specific time.
Use array format to save your model outputs and states only if the logged data meets all these conditions:
Data is all scalars or all vectors (or all matrices for states)
Data is all real or all complex
Data all has the same data type
Data includes bus signals
If your model outputs and states do not meet these conditions, use the
Structure with time output formats
(see Structure with 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 Configuration Parameters > Data Import/Export pane. By default, the structures are
xout for states and
yout for output.
The structure used to save outputs has two top-level fields:
Contains a vector of the simulation times.
Contains an array of substructures, each of which corresponds to a model output port.
Each substructure has four fields:
Contains the outputs for the corresponding output port.
If outputs are scalars or vectors —
valuesfield is a matrix each of whose rows represent an output at the time specified by the corresponding time vector element.
If the outputs are matrix (2-D) values —
valuesfield is a 3-D array of dimensions M-by-N-by-T. M-by-N is the dimensions of the output signal and T is the number of output samples.
If T = 1 — MATLAB drops the last dimension. Therefore, the
valuesfield is an M-by-N matrix.
Specifies the dimensions of the output signal.
Specifies the label of the signal connected to the output port, S-Function block, or the type of state (continuous or discrete). The label is
CSTATE, except for S-Function block state labels. For S-Function block state labels for discrete states, the label is the name of the state (instead of
Specifies the name of the corresponding output port or block with states.
signalsfield records the final state of a block that resides in the referenced model, contains a value of
1. Otherwise, the value is false (
The following example shows the structure-with-time format for a nonreferenced model.
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:
timefield contains a vector of the simulation times.
The field contains an array of substructures, each of which corresponds to one of the states of the model.
signals structure has four fields:
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
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
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.
Simulink can read back simulation data saved to the MATLAB workspace in the
Structure with time output format. See
Examples of Specifying Signal and Time Data for more information.
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