sosfilt

Builtin index · Signal processing

result = sosfilt(filt, x)

Input: filt, x · Output: result

What it is

filt: a Model (kind "filter", field sos or b); x: a length-N vector or Signal.

Overloads

x can be vector or Signal.

2 forms. Each carries its own inputs, outputs and worked example — pick the tab for the one you are calling.

IIR filter (sos) FIR filter (b)

Code	Input	Output	Description
`result = sosfilt(filt, x)`	`filt` Model`filt` a `Model` with a `sos` field (`butter`/`ellip`/`cheby1`/`cheby2`). `x` vector or SignalRuns `x` through the biquad cascade section by section.	`Signal` Signalkeeping `x`'s own `Fs` on the way out, when `x` is a `Signal` `b` —FIR	—

Examples

Written for this form and run by the build -- the output below is what the engine actually produced.

fs = 100
t = (0 to 19) / fs
x = sin(2*pi*10*t)
iir = butter(2, "low", 20, fs)
y_iir = sosfilt(iir, x)
print("IIR-filtered length: {length(y_iir)}")   # IIR-filtered length: 20

output

IIR-filtered length: 20

Code	Input	Output	Description
`result = sosfilt(filt, x)`	`filt` Model`filt` a `Model` with a `b` field (`fir1`/`firls`). `x` vector or SignalRuns `x` through `conv(x, b, "full")`, truncated back to `length(x)` — no biquad state at all.	`Signal` Signalkeeping `x`'s own `Fs` on the way out, when `x` is a `Signal` `b` —FIR	—

Examples

Written for this form and run by the build -- the output below is what the engine actually produced.

fs = 100
t = (0 to 19) / fs
x = sin(2*pi*10*t)
fir = fir1(6, 20, kind="low", fs=fs)
y_fir = sosfilt(fir, x)
print("FIR-filtered length: {length(y_fir)}")   # FIR-filtered length: 20

output

FIR-filtered length: 20