Parameter Quantization Advisor

Inspect numerical issues related to parameter quantization

Since R2022b

Description

The Parameter Quantization Advisor app provides details on numerical issues related to parameter quantization. Using this app, you can:

• Explore in detail the effects of parameter quantization on your model.

• Explore the parameters in a model that have quantization issues, including parameters with a structure value, bus objects, and Simulink.Parameter objects.

• Filter quantization issues that result from parameter overflow, underflow, and precision loss.

• Sort quantization issues based on bits of error, absolute error, or relative error.

• Adjust parameter precision loss diagnostic configuration parameters.

Required Products

You must have a Fixed-Point Designer™ license to use the Parameter Quantization Advisor app with a model that contains fixed-point data types. Without a Fixed-Point Designer license, you can use the app only on models that contain built-in data types, including double, single, int8, int16, int32, int64, uint8, uint16, uint32, and uint64. This requirement applies to both dialog and run-time data types.

Open the Parameter Quantization Advisor App

• Simulink^® Toolstrip: On the Debug tab, under Diagnostics, click Parameter Quantization Advisor. (since R2025a)

• Diagnostic Viewer: From a numeric diagnostic warning or error, under Suggested Actions, click Open.

• MATLAB^® Command Window: Enter this command, where model_name is the name of the model. (since R2025a)

  parameterQuantizationAdvisor("model_name")

Examples

Explore Parameter Precision Loss

Use the Parameter Quantization Advisor app to explore parameter precision loss in a Simulink® model.

Open the sldemo_fuelsys model from the Model Fault-Tolerant Fuel Control System example.

openExample('simulink_automotive/ModelingAFaultTolerantFuelControlSystemExample')

Enable parameter precision loss diagnostics. In the Configuration Parameters dialog box, under Diagnostics > Data Validity, in the Parameters section, set the Detect precision loss diagnostic to warning.

Simulate the model.

The Diagnostic Viewer displays 21 warnings for parameter precision loss.

To inspect the details of these diagnostics in the Parameter Quantization Advisor app, from the second bullet under Suggested Actions section, click Open. By default, the app shows quantization issues related to overflow, underflow, and precision loss.

In this example, the model has only precision loss issues, indicated by the blue square in the Issue column of the table. You can confirm this by unselecting the Precision Loss filter in the toolstrip to hide the precision loss errors.

You can use the Parameter Explorer pane to search and navigate to parameters in the model that have quantization loss. The Parameter Details pane shows that all of the precision loss warnings are due to conversion from double precision to single precision data types.

To suppress these precision loss warnings, select the Suppress double to single detection check box. Click Refresh Data to apply this setting to the model, compile the model, and update the data in the app. After suppressing double-to-single precision loss diagnostics, the app indicates that the model has no quantization issues.

Alternatively, if you want to filter parameter precision loss diagnostics beneath a certain threshold, use the Absolute difference threshold and Relative difference threshold settings. You can also set the Detect precision loss diagnostic to none, warning, or error from the Parameter Quantization Advisor toolstrip.

You can view the current model configuration parameter settings in the Model Configuration Parameters pane. To adjust the model parameters related to overflow and underflow detection, click the Configuration Parameters button to open the Configuration Parameters dialog box. Set the Detect precision loss diagnostic to none, then click OK. After applying the new settings, in the Parameter Quantization Advisor app, click Refresh Data to compile the model and update the data displayed in the app.

Programmatic Use

parameterQuantizationAdvisor("model_name") opens the Parameter Quantization Advisor app for the specified model.

parameterQuantizationAdvisor("block_path","parameter_name") opens the Parameter Quantization Advisor app with the specified block and parameter selected.

parameterQuantizationAdvisor("block_path","structure_value") opens the Parameter Quantization Advisor app for a parameter with a structure value.

parameterQuantizationAdvisor("model_name","Simulink.Parameter_object_name") opens the Parameter Quantization Advisor app for a Simulink.Parameter object.

Limitations

• Parameters with nested structures are not supported.

• The Refresh Data button applies app settings to the model, compiles the model, and updates the data in the app. This button does not update model data in the Diagnostic Viewer and elsewhere.

Tips

• The Parameter Explorer pane displays a hierarchical tree of parameters in the model that have quantization issues. You can enter a string to search for a particular element in this tree. To view additional details, select the parameter you want to inspect.

• When you filter data in the app, the Parameter Explorer pane reflects this filtering. Parameters with lossless elements, parameters with quantization issues filtered in the app, and parameters with suppressed quantization issues display when you select the Parameters Without Diagnostics filter. (since R2025a)

• The Parameter Quantization Advisor app reports information for these quantization issues:

  • Detect underflow

  • Detect overflow

    • Bits of error threshold

  • Detect precision loss

    • Suppress double to single detection

    • Absolute difference threshold

    • Relative difference threshold

  By default, the Parameter Quantization Advisor app hides the parameter overflow and precision loss diagnostics that the above configuration parameters suppress or filter out via threshold settings. To display these diagnostics in the app, use the Parameters Without Diagnostics button.

• The Parameter Quantization Advisor app reports details on quantization issues for tunable and nontunable parameters that experience quantization loss.

• When the model uses a referenced configuration set, the Parameter Quantization Advisor app overrides the local configuration settings only. The app highlights the locally overridden configuration parameters in blue. For more information on sharing a configuration set with multiple models, see Share a Configuration with Multiple Models. (since R2025a)

Version History

Introduced in R2022b

R2025a: Simplified toolstrip and app data refresh

The Parameter Quantization Advisor has a simplified toolstrip design. When you adjust settings in the app, the Parameter Quantization Advisor applies the Detect precision loss settings to the model. To refresh data in the app, click Refresh Data. In previous releases, you clicked the Apply and Update button to apply new settings to the model and update the app data.

Data in the app is refreshed when the app is relaunched, when you update the model, or when you click the Refresh Data button. In previous releases, the app data did not update when you updated the model.

R2025a: Open app from Simulink model

There are two new ways to open the Parameter Quantization Advisor app from a Simulink model:

• Open the Parameter Quantization Advisor app from the Simulink toolstrip. On the Debug tab, under Diagnostics, click Parameter Quantization Advisor

• Use the model name to open the Parameter Quantization Advisor app from the MATLAB Command Window.

  parameterQuantizationAdvisor("model_name")

R2024b: Access precision loss parameters using toolstrip options

The Parameter Quantization Advisor app now includes options for adjusting parameter precision loss diagnostic configuration parameters in the Precision Loss section of the toolstrip.

View the current state of parameter precision loss diagnostic configuration parameters in the Model Configuration Parameters pane of the Parameter Quantization Advisor app.

R2024a: Toolstrip-based UI

The Parameter Quantization Advisor app interface now includes a simplified toolstrip with new features.

• Filter data:

  • Use the Overflow, Underflow, and Precision Loss filters to show or hide diagnostic data.

  • Use the Parameters Without Diagnostics filter to show or hide issues that are lossless and quantization issues that are filtered out due to configuration parameter settings.

• Open the Configuration Parameters dialog box directly from the app using the Model Settings button.

• Refresh data in the app using the Refresh Data button.

• The app now automatically hides diagnostics that are suppressed with Simulink.SuppressedDiagnostic.

R2024a: Support for structures, bus, and Simulink.Parameter objects

The Parameter Quantization Advisor app now supports structures, bus objects, and Simulink.Parameter objects. Use the MATLAB Command Window to open the app for a parameter with a structure value or for a Simulink.Parameter object.

R2023b: Launch from Command Window, search to navigate results, and improved view filtering

Launch the Parameter Quantization Advisor app from the MATLAB Command Window.

Enter a string in the Parameter Explorer pane to search for a particular element within the results. The Parameter Explorer pane displays results for parameters that have quantization issues.

Improved view filtering allows you to configure which columns to display in the parameter diagnostics table.

R2023a: View multiple parameters

You can now explore all parameters associated with a model by using the Parameter Quantization Advisor.

Additionally, the Parameter Quantization Advisor app has expanded support for the MATLAB Function block, Stateflow^® chart parameters, the FIR Decimation (DSP System Toolbox) block, and the FIR Interpolation (DSP System Toolbox) block.