OnezeroUG Class Reference

OnezeroUG is a one-zero (FIR) fiter useful for mild low and high-pass filtering. More...

#import <OnezeroUG.h>

List of all members.

Public Member Functions
(id)	- setInput:
	Sets the input patchpoint to aPatchPoint.
(id)	- setOutput:
	Sets the output patchpoint to aPatchPoint.
(id)	- setB0:
	Sets the filter's gain.
(id)	- setB1:
	Sets the filter's coefficient.
(id)	- clear
	Clears the filter by setting the delayed sample (the previous input sample) to 0.0.
Static Public Member Functions
(BOOL)	+ shouldOptimize:
	Specifies that all arguments are to be optimized if possible except the filter state.

---

Detailed Description

OnezeroUG is a one-zero (FIR) fiter useful for mild low and high-pass filtering.

OnezeroUG is a one-zero filter that's implemented by adding the previous input sample (initialized as 0.0) to the current input sample:

output = (b0 * input) + (b1 * previousInput)

previousInput = input

Note that the two samples have their own scalers:

• b0 scales the input sample; this is the gain of the filter. Effective gain values are between 0.0 and 1.0 (a negative gain is the same as its absolute value, but with a 180 degree phase shift).

• b1 scales the previous input sample. This is the filter's coefficient: If b1 is less than 0.0, the OnezeroUG is a high-pass filter; if it's greater than 0.0, the object is a low-pass filter. For stability, the value of b1 should be between -1.0 and 1.0 (non-inclusive).

Similar to the OnezeroUG is the OnepoleUG; it, too, is either a low-pass or a high-pass filter, but the frequency roll-off is steeper than with a OnezeroUG. You should also note that the high-pass/low-pass determination with regard to the sign of the coefficent is switched in the OnepoleUG.

Memory Spaces

OnezeroUGab a output b input

---

Member Function Documentation

- (id) setInput:

(id)

aPatchPoint

Sets the input patchpoint to aPatchPoint.

Parameters:

aPatchPoint

is an id.

Returns:

Returns an id. Returns nil if the argument isn't a patchpoint; otherwise returns self.

- (id) setOutput:

(id)

aPatchPoint

Sets the output patchpoint to aPatchPoint.

Parameters:

aPatchPoint

is an id.

Returns:

Returns an id. Returns nil if the argument isn't a patchpoint; otherwise returns self.

- (id) setB0:

(double)

value

Sets the filter's gain.

Parameters:

value

is a double.

Returns:

Returns self. Effective gain values are between 0.0 and 1.0 (a negative gain is the same as its absolute value, but with a 180 degree phase shift).

- (id) setB1:

(double)

value

Sets the filter's coefficient.

Parameters:

value

is a double.

Returns:

Returns self. If value is less than 0.0, the OnezeroUG is a high-pass filter; if it's greater than 0.0, the object is a low-pass filter. For stability, the value should be between -1.0 and 1.0.

+ (BOOL) shouldOptimize:

(unsigned)

arg

Specifies that all arguments are to be optimized if possible except the filter state.

Parameters:

arg

is an unsigned.

Returns:

Returns an BOOL.

- (id) clear

Clears the filter by setting the delayed sample (the previous input sample) to 0.0.

Returns:

Returns self.

---

The documentation for this class was generated from the following file:

• OnezeroUG.h