ismaxphase() - Signal Processing

flag = ismaxphase(b,a) returns
a logical output, flag, equal to true if
the filter specified by numerator coefficients, b,
and denominator coefficients, a, is a maximum
phase filter. flag = ismaxphase(sos) returns true if
the filter specified by second order sections matrix, sos,
is a maximum phase filter. sos is a K-by-6
matrix, where the number of sections, K, must be
greater than or equal to 2. Each row of sos corresponds
to the coefficients of a second order (biquad) filter. The ith
row of the sos matrix corresponds to [bi(1)
bi(2) bi(3) ai(1) ai(2) ai(3)].flag = ismaxphase(d) returns true if
the digital filter, d, has maximum phase. Use designfilt to generate d based
on frequency-response specifications.flag = ismaxphase(...,tol) uses
the tolerance, tol, to determine when two numbers
are close enough to be considered equal. If not specified, tol,
defaults to eps^(2/3).flag = ismaxphase(hs,...) returns trueif
the filter System object™ hs is a maximum phase
filter. You must have the DSP System Toolbox™ software to use this
syntax.flag = ismaxphase(hs,'Arithmetic',arithtype) analyzes
the filter System object hs based on the specified arithtype. arithtype can
be 'double', 'single', or 'fixed'.
When you specify 'double' or 'single',
the function performs double- or single-precision analysis. When you
specify 'fixed' , the arithmetic changes depending
on the setting of the CoefficientDataType property
and whether the System object is locked or unlocked. You must
have the DSP System Toolbox software to use this syntax. Details for Fixed-Point Arithmetic

System Object StateCoefficient Data TypeRule
Unlocked'Same as input'The function assumes that the coefficient data type is signed,
16 bit, and autoscaled. The function performs fixed-point analysis
based on this assumption.
Unlocked'Custom'The function performs fixed-point analysis based on the setting
of the CustomCoefficientsDataType property.
Locked'Same as input'When the input data type is 'double' or 'fixed',
the function assumes that the coefficient data type is signed, 16-bit,
and autoscaled. The function performs fixed-point analysis based on
this assumption.
Locked'Custom'The function performs fixed-point analysis based on the setting
of the CustomCoefficientsDataType property.


When you do not specify the arithmetic for non-CIC structures,
the function uses double-precision arithmetic if the filter System object is
in an unlocked state. If the System object is locked, the function
performs analysis based on the locked input data type. CIC structures
only support fixed-point arithmetic.flag = ismaxphase(h) returns true if
the dfilt filter object h is
a maximum phase filter.

Syntax

flag = ismaxphase(b,a)flag = ismaxphase(sos)flag = ismaxphase(d)flag = ismaxphase(...,tol)flag = ismaxphase(hs,...)flag = ismaxphase(hs,'Arithmetic',arithtype)flag = ismaxphase(h)

Example

Maximum- and Minimum-Phase FiltersOpen This Example
Design maximum-phase and minimum-phase lattice filters and verify their phase type.
k = [1/6 1/1.4];
bmax = latc2tf(k,'max');
bmin = latc2tf(k,'min');
max_flag = ismaxphase(bmax)
min_flag = isminphase(bmin)

max_flag =

     1


min_flag =

     1

Given a filter defined with a set of single precision numerator and denominator coefficients, check if it is maximum phase for different values of the tolerance.b = single([1 -0.9999]);
a = single([1 0.45]);
max_flag1 = ismaxphase(b,a)
max_flag2 = ismaxphase(b,a,1e-3)

max_flag1 =

     0


max_flag2 =

     1

Output / Return Value

Limitations

Alternatives / See Also

Reference