addAlgorithmProperty

R2026b

Add algorithm properties for code replacement table entry

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Syntax

addAlgorithmProperty(hEntry,Name=Value)

Description

addAlgorithmProperty(hEntry,Name=Value) adds algorithm property settings to the conceptual representation of a code replacement table entry. For example, use this function to adjust the algorithms applied by lookup table functions.

Examples

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  • This example shows how to use the addAlgorithmProperty function to configure the code generator to apply these methods when replacing code for the lookup1D function:

    • Clip extrapolation

    • Linear interpolation

    • Binary or linear index search

    hLib = RTW.TflTable;

hEnt = RTW.TflCFunctionEntry;
hEnt.setTflCFunctionEntryParameters( ...
                    Key="lookup1D", ...
                    Priority=100, ...
                    ImplementationName="my_Lookup1D_Repl", ...
                    ImplementationHeaderFile="my_Lookup1D.h", ...
                    ImplementationSourceFile="my_Lookup1D.c", ...
                    GenCallback="RTW.copyFileToBuildDir");

arg = hEnt.getTflArgFromString('y1','double');
arg.IOType = 'RTW_IO_OUTPUT';
hEnt.addConceptualArg(arg);

arg = hEnt.getTflArgFromString('u1','double');
hEnt.addConceptualArg(arg);

arg = RTW.TflArgMatrix('u2','RTW_IO_INPUT','double');
arg.DimRange = [0 0; Inf Inf];
hEnt.addConceptualArg(arg);

arg = RTW.TflArgMatrix('u3', 'RTW_IO_INPUT', 'double');
arg.DimRange = [0 0; Inf Inf];
hEnt.addConceptualArg(arg);

hEnt.addAlgorithmProperty(ExtrapMethod="Clip");
hEnt.addAlgorithmProperty(InterpMethod="Linear point-slope");
hEnt.addAlgorithmProperty(IndexSearchMethod="Linear search");

Input Arguments

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Code replacement table entry, previously returned by calling the function RTW.TflCFunctionEntry or RTW.TflCOperationEntry.

Name-Value Arguments

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Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: Name=y1

In a lookup table block, the ApplyFullPrecisionForLinearInterpolation value specifies whether or not to use full-precision fixed-point algorithm for linear interpolation lookup when possible. For a code replacement entry, the value specifies whether to match generated lookup functions that use full-precision table lookup.

If you set ApplyFullPrecisionForLinearInterpolation to on in a code replacement entry:

  • If the value on the block is set to on but the code generator was not able to use the full-precision fixed-point algorithm for the generated lookup function, the entry does not match the generated function.

  • A match can cause a numerical mismatch between simulation and code generation if the implementation algorithm is different from the algorithm used for simulation.

Set the BPPower2Spacing value to on if you want to replace blocks whose breakpoints are the power of 2 spaced values by the user-defined function specified in the code replacement library. Set the value to off if you want to replace blocks whose breakpoints are not the power of 2 spaced values by the user-defined function specified in the code replacement library.

The ExtrapMethod value specifies which method to use to extrapolate values for inputs that fall outside the range of a breakpoint data set.

Example: ExtrapMethod="Clip"

The IndexSearchMethod value specifies the method of calculating table indices. For evenly spaced breakpoint sets, you achieve optimal speed by selecting Evenly spaced points to calculate table indices. For unevenly spaced breakpoint sets, use Linear search or Binary search.

Example: IndexSearchMethod="Evenly spaced points"

The InterpMethod value specifies the method of interpolation between breakpoint values.

Example: InterpMethod="Linear point-slope"

The RemoveProtectionInput value specifies whether or not to include code that checks for out-of-range input values. If your input values are not out of range, you can set the RemoveProtectionInput to off.

Example: RemoveProtectionInput="off"

The RndMeth value specifies the rounding mode for fixed-point lookup table calculations.

Example: RndMeth="Zero"

The SaturateOnIntegerOverflow value specifies the method of overflow action. If you set the value to off, overflows wrap to the appropriate value that is represented by the data type. Otherwise, overflows saturate to either the minimum or maximum value that the data type can represent.

Example: SaturateOnIntegerOverflow="on"

If you want to enable tunable table size in the generated code, set the SupportTunableTableSize value to on.

Example: SupportTunableTableSize="on"

The UseLastTableValue value specifies the indexing convention to use to address the last element of a breakpoint set and its corresponding table value.

Example: UseLastTableValue="on"

Set the UseRowMajorAlgorithm value to on to enable using row-major algorithms. Set the value to off to use column-major algorithms.

Example: UseRowMajorAlgorithm="on"

Version History

Introduced in R2014b

See Also

Topics