isreal
Verify that discrete-time filter System object is real
Syntax
Description
Examples
Check if Filter Coefficients Are Real
Create a dsp.SOSFilter
System object™. Pass a fixed-point input to the object. Test the coefficients of the fixed-point filter to see if they are strictly real.
d = fdesign.lowpass('n,fp,ap,ast',5,0.4,0.5,20); sosFilter = design(d,'ellip',SystemObject=true)
sosFilter = dsp.SOSFilter with properties: Structure: 'Direct form II' CoefficientSource: 'Property' Numerator: [3x3 double] Denominator: [3x3 double] HasScaleValues: true ScaleValues: [0.6252 0.5432 0.4861 1] Use get to show all properties
IsRealBefore = isreal(sosFilter)
IsRealBefore = logical
1
Pass a fixed-point input to the object.
fiInput = fi(randn(1000,2),1,32,16); fiOutput = sosFilter(fiInput); IsRealAfter = isreal(sosFilter)
IsRealAfter = logical
1
The isreal
function returns a value of 1, indicating that the filter coefficients are real.
Input Arguments
sysobj
— Input filter
filter System object™
Output Arguments
flag
— Flag to determine whether filter coefficients are real
1
| 0
Flag to determine whether the filter coefficients are real, returned as a logical
scalar. If the filter coefficients are real, isreal
returns a
logical 1
, else it returns a logical 0
.
Data Types: logical
Version History
Introduced in R2011aR2024b: Support for dsp.VariableFIRDecimator
and dsp.VariableFIRInterpolator
Objects
Starting in R2024b, the isreal
analysis function supports the
dsp.VariableFIRDecimator
and dsp.VariableFIRInterpolator
objects.
R2024b: dsp.BiquadFilter
object warns
The dsp.BiquadFilter
object issues a warning and will be removed in a
future release. Use the dsp.SOSFilter
object
instead. For more information on how to replace your existing code, see the
Compatibility Considerations section in the dsp.BiquadFilter
reference page.
R2024b: Support for dsp.DCBlocker
object
Starting in R2024b, this function supports the dsp.DCBlocker
object.
R2023b: Support for dsp.ParallelFilter
and dsp.Delay
Objects
Starting in R2023b, the isreal
analysis function supports the
dsp.ParallelFilter
and the dsp.Delay
objects.
R2023b: dsp.BiquadFilter
object will be removed
The dsp.BiquadFilter
object will be removed in a future release. Use
the dsp.SOSFilter
object
instead.
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