[zphase,w]
= zerophase(sysobj)
returns the zero-phase response vector, zphase, and the corresponding
frequency vector, w, in radians/sample of the filter System object™ based on the current filter coefficients.

[zphase,w]
= zerophase(sysobj,n)
returns the n-point zero-phase response vector and the corresponding
n-point frequency vector in radians/sample of the filter System object.

[zphase,w]
= zerophase(___,'Arithmetic',arithType)
analyzes the filter System object based on the arithmetic specified in arithType using
either of the previous syntaxes.

n — Number of points over which zero-phase response is evaluated 8192 (default) | positive integer

Number of points over which the zero-phase response is evaluated around the upper
half of the unit circle. For an FIR filter where n is a power of
two, the computation is done faster using FFTs.

Data Types: double

arithType — Arithmetic type 'double' (default) | 'single' | 'Fixed'

Arithmetic used in the filter analysis, specified as 'double',
'single', or 'Fixed'. When the arithmetic
input is not specified and the filter System object is unlocked, the analysis tool assumes a double-precision filter. When the
arithmetic input is not specified and the System object is locked, the function performs the analysis based on the data type of
the locked input.

The 'Fixed' value applies to filter System objects with fixed-point
properties only.

When the 'Arithmetic' input argument is specified as
'Fixed' and the filter object has the data type of the
coefficients set to 'Same word length as input', the arithmetic
analysis depends on whether the System object is unlocked or locked.

unlocked –– The analysis object function cannot determine the coefficients
data type. The function assumes that the coefficients data type is signed,
has a 16-bit word length, and is auto scaled. The function performs
fixed-point analysis based on this assumption.

locked –– When the input data type is 'double' or
'single', the analysis object function cannot
determine the coefficients data type. The function assumes that the data
type of the coefficients is signed, has a 16-bit word length, and is auto
scaled. The function performs fixed-point analysis based on this
assumption.

To check if the System object is locked or unlocked, use the isLocked function.

When the arithmetic input is specified as 'Fixed' and the filter
object has the data type of the coefficients set to a custom numeric type, the object
function performs fixed-point analysis based on the custom numeric data type.

Zero-phase response vector, evaluated at n equally-spaced
points around the upper half of the unit circle, returned as a vector. If
n is not specified, the function uses a default value of
8192.

Data Types: double

w — Frequency vector vector

Frequency vector of length n in radians/sample.
w consists of n equally-spaced points around
the upper half of the unit circle (from 0 to π radians/sample). If
n is not specified, the function uses a default value of
8192.

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