LUTCompressionResult

Optimized lookup table data for all Lookup Table blocks in a system

Since R2020a

Description

A LUTCompressionResult object contains the optimized lookup table data for all Lookup Table blocks in a system. To create a LUTCompressionResult object, use the FunctionApproximation.compressLookupTables function. To replace the lookup tables in your system with the optimized version, use the replace function.

Creation

Create a LUTCompressionResult object using FunctionApproximation.compressLookupTables.

Properties

MemoryUnits — Units for memory usage

'bytes' (default) | 'bits' | 'Kb' | 'Kibit' | 'KB' | 'KiB' | 'Mb' | 'Mibit' | 'MB' | 'MiB' | 'Gb' | 'Gibit' | 'GB' | 'GiB'

Units for MaxMemoryUsage property, specified as 'bits', 'bytes', or one of the other enumerated options.

Data Types: char

MemoryUsageTable — Table summarizing the effects of compression

table

Table summarizing the effects of compression. The table contains one row for each lookup table compressed in the system and its corresponding memory savings.

Data Types: table

NumLUTsFound — Number of lookup tables found in system

integer-valued scalar

Number of lookup tables found in the specified system, specified as an integer-valued scalar.

Data Types: double

NumImprovements — Number of lookup tables compressed

integer-valued scalar

Number of lookup tables compressed in the system, specified as an integer-valued scalar.

Data Types: double

TotalMemoryUsed — Total memory of all lookup tables in system before compression

scalar

Total memory of all lookup tables in the system before compression, returned as a scalar. You can specify the units of this property by using the MemoryUnits property.

Data Types: double

TotalMemoryUsedNew — Total memory of all lookup tables in system after compression

scalar

Total memory of all lookup tables in the system after compression, returned as a scalar. You can specify the units of this property by using the MemoryUnits property.

Data Types: double

TotalMemorySavings — Difference between total memory before compression and after compression

scalar

Difference between the total memory of all lookup tables in the system before and after compression, returned as a scalar. You can specify the units of this property by using the MemoryUnits property.

Data Types: double

TotalMemorySavingsPercent — Percentage reduction in memory used by lookup tables in the system

scalar

Percentage reduction in the memory used by the lookup tables in the system after compression, returned as a scalar.

Data Types: double

SUD — System containing compressed lookup tables

character vector

System containing compressed lookup tables, returned as a character vector. SUD is the same as the system input argument of the FunctionApproximation.compressLookupTables function.

Data Types: char

WordLengths — Word lengths used for breakpoints and table data in the compressed lookup tables

scalar | vector

Word lengths used for breakpoints and table data in the compressed lookup tables, returned as a scalar or vector of integers.

Data Types: double

FindOptions — Options for finding lookup tables in system

Simulink.FindOptions object

Simulink.FindOptions object specifying options for finding lookup tables in the system.

Object Functions

replace	Replace all Lookup Table blocks with compressed lookup tables
revert	Revert compressed Lookup Table blocks to original versions

Examples

Compress All Lookup Table Blocks in a System

This example shows how to compress all Lookup Table blocks in a system.

Open the model containing the lookup tables that you want to compress.

system = 'sldemo_fuelsys';
open_system(system)

Use the FunctionApproximation.compressLookupTables function to compress all of the lookup tables in the model. The output returns all blocks that are modified and the memory savings for each.

compressionResult = FunctionApproximation.compressLookupTables(system)

- Found 5 supported lookup tables
- Percent reduction in memory for compressed solution
	-  2.37% for sldemo_fuelsys/fuel_rate_control/airflow_calc/Pumping Constant
	-  2.37% for sldemo_fuelsys/fuel_rate_control/control_logic/Throttle.throttle_estimate/Throttle Estimation
	-  3.55% for sldemo_fuelsys/fuel_rate_control/control_logic/Speed.speed_estimate/Speed Estimation
	-  6.38% for sldemo_fuelsys/fuel_rate_control/control_logic/Pressure.map_estimate/Pressure Estimation
	-  9.38% for sldemo_fuelsys/fuel_rate_control/airflow_calc/Ramp Rate Ki

compressionResult = 

  LUTCompressionResult with properties:

                  MemoryUnits: bytes
             MemoryUsageTable: [5x5 table]
                 NumLUTsFound: 5
              NumImprovements: 5
              TotalMemoryUsed: 6024
           TotalMemoryUsedNew: 5796
           TotalMemorySavings: 228
    TotalMemorySavingsPercent: 3.7849
                          SUD: 'sldemo_fuelsys'
                  WordLengths: [8 16 32]
                  FindOptions: [1x1 Simulink.internal.FindOptions]
                      Display: 1

Use the replace function to replace each Lookup Table block with a block containing the original and compressed version of the lookup table.

replace(compressionResult);

You can revert the lookup tables back to their original state using the revert function.

revert(compressionResult);

Version History

Introduced in R2020a