Vector of SOS filters for cumulative sections

`h = cumsec(hd)`

h = cumsec(hd,indices)

h = cumsec(hd,indices,secondary)

cumsec(hd,...)

h = cumsec(hs)

h = cumsec(hs,Name,Value)

`h = cumsec(`

returns
a vector `hd`

)`h`

of SOS filter objects with the cumulative
sections. Each element in `h`

is a filter with the
structure of the original filter. The first element is the first filter
section of `hd`

. The second element of `h`

is
a filter that represents the combination of the first
and second sections of `hd`

. The third element of `h`

is
a filter which combines sections 1, 2, and 3 of `hd`

.
This pattern continues until the final element of `h`

contains
all the sections of `hd`

and should be identical
to `hd`

.

`h = cumsec(`

returns
a vector `hd`

,`indices`

)`h`

of SOS filter objects whose indices
into the original filter are in the vector `indices`

.

`h = cumsec(`

uses
the secondary scaling points `hd`

,`indices`

,`secondary`

)`secondary`

in the sections
to determine where the sections should be split.

`cumsec(`

uses
FVTool to plot the magnitude response of the cumulative sections.`hd`

,...)

`h = cumsec(`

returns
the cumulative sections of the `hs`

)`dsp.BiquadFilter`

filter System object™ `hs`

.
You can also use the optional input arguments `indices`

and `secondary`

with
this syntax. You can also omit the output argument `h`

to
use FVTool to plot the magnitude response of the cumulative sections.

`h = cumsec(`

returns
the cumulative sections of the filter System object `hs`

,`Name,Value`

)`hs`

with
additional options specified by one or more `Name,Value`

pair
arguments.

To demonstrate how `cumsec`

works, this example
plots the relative responses of the sections of a sixth-order filter
SOS filter with three sections. Each curve adds one more section to
form the filter response.

hs = fdesign.lowpass('n,fc',6,.4); hd = butter(hs); h = cumsec(hd); hfvt = fvtool(h); legend(hfvt,'First Section','First Two Sections','Overall Filter');

Was this topic helpful?