AllocIIRFilterPtr
Advanced Analysis Library Only
IIRFilterPtr AllocIIRFilterPtr (int type, int order);
Purpose
Allocates and initializes the filterInformation structure. This function returns a pointer to the filter structure for use with the IIR cascade filter coefficient design calls.
You input the type of the filter, such as lowpass, highpass, bandpass, or bandstop, and the order. AllocIIRFilterPtr allocates the filter structure and the internal coefficient arrays and internal filter state array.
Parameters
| Input | ||
| Name | Type | Description |
| type | int | Controls the filter type of IIR filter coefficients. lowpass = 0 (default) highpass = 1 bandpass = 2 bandstop = 3 |
| order | int | The order of the IIR filter. The default value is 3. |
Return Value
| Name | Type | Description |
| filterInformation | IIRFilterPtr | Pointer to the filter structure that contains the filter coefficients and the internal filter information. Call this function to allocate filterInformation before you call one of the cascade IIR filter design functions. When an error occurs, filterInformation is zero. The definition of the filter structure is as follows: typedef struct { intnum type; /* type of filter (lp, hp, bp, bs) */ |
Additional Information
Library: Advanced Analysis Library
Include file: analysis.h
LabWindows/CVI compatibility: LabWindows/CVI 4.0 and later
Examples
Refer to the following examples that use the AllocIIRFilterPtr function:
- analysis\iirfiltr.cws
Open example - analysis\transmit.cws
Open example