Verify that discrete-time filter System object is allpass
Create an allpass filter using the
apass = dsp.AllpassFilter
apass = dsp.AllpassFilter with properties: Structure: 'Minimum multiplier' AllpassCoefficients: [-0.7071 0.5000] TrailingFirstOrderSection: false
Verify that the filter is an allpass filter by visualizing the magnitude response in
Now verify that the filter is an allpass filter using the
ans = logical 1
sysobj— Filter System object
Input filter, specified as one of the following filter System objects:
tol— Tolerance value
eps^(2/3)(default) | positive scalar
Tolerance value to determine when two numbers are close enough to be considered
equal, specified as a positive scalar. If not specified,
eps^(2/3). Specifying a tolerance may be most helpful in
fixed-point allpass filters.
arithType— Arithmetic type
Arithmetic used in the filter analysis, specified as
'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.
'Fixed' value applies to filter System objects with fixed-point
'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
'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
To check if the System object is locked or unlocked, use the
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.
flag— Flag to determine if filter is allpass
Flag to determine if the filter is allpass, returned as a logical:
1 –– Filter is allpass.
0 –– Filter is not allpass.