6 Recursive Adaptive Algorithms

This chapter documents the functions used to create, initialize, and update the coefficients of recursive adaptive filters (Section 2.2.3). Table 6.1 summarizes the recursive adaptive functions functions and gives a short description and a pointer to the reference page of each function.

Table 6.1: Functions for creating, initializing, and updating recursive adaptive filters.

Function Name	Reference	Short Description
asptcsoiir2	6.1	Cascaded Second Order type-2 IIR adaptive filter.
aspteqerr	6.2	Equation Error IIR adaptive algorithm.
asptouterr	6.3	Output Error IIR adaptive algorithm.
asptsharf	6.4	Simple Hyperstable Adaptive Recursive Filter (SHARF).
asptsoiir1	6.5	Second Order IIR adaptive algorithm type-1.
asptsoiir2	6.6	Second Order IIR adaptive algorithm type-2.
init_ csoiir2	6.7	Initialize Cascaded Second Order IIR adaptive filter.
init_ eqerr	6.8	Initialize Equation Error IIR adaptive filter.
init_ outerr	6.9	Initialize Output Error IIR.
init_ sharf	6.10	Initialize Simple Hyperstable Adaptive Recursive Filter.
init_ soiir1	6.11	Initialize Second Order IIR adaptive algorithm type-1.
init_ soiir2	6.12	Initialize Second Order IIR adaptive algorithm type-2.

Each function is documented in a separate section including the following information related to the function:

• Purpose: Short description of the algorithm implemented by this function.
• Syntax: Shows the function calling syntax. If the function has optional parameters, this section will have two calling syntaxes. One with only the required formal parameters and one with all the formal parameters.
• Description: Detailed description of the function usage with explanation of its input and output parameters.
• Example: A short example showing typical use of the function. The examples listed can be found in the ASPT/test directory of the ASPT distribution. The user is encouraged to copy from those examples and paste in her own applications.
• Algorithm: A short description of the operations internally performed by the function.
• Remarks: Gives more theoretical and practical remarks related to the usage, performance, limitations, and applications of the function.
• Resources: Gives a summary of the memory requirements and number of multiplications, addition/subtractions, and division operations required to implement the function in real time. This can be used to roughly calculate the MIPS (Million Instruction Per Second) required for a specific platform knowing the number of instructions the processor needs to perform each operation.
• See Also: Lists other functions that are related to this function.
• Reference: Lists literature for more information on the function.