# filter_zerophase

Version:
Last Modified: March 15, 2017

Applies a one-dimensional zero-phase filter. filter_zerophase applies the filter, reverses the order of the resulting signal, applies the filter again, and reverses the signal a second time, resulting in zero-phase behavior. filter_zerophase works column-wise for matrices.

## Syntax

y = filter_zerophase(b, a, x)
Legacy name: filtfilt

## b

Forward filter coefficients. b is a vector.

## a

Backward filter coefficients. If the first backward filter coefficient does not equal 1, MathScript normalizes the elements in a by the first backward filter coefficient. a is a vector.

## x

Signal to filter. x is a real or complex vector or matrix.

## y

Filtered signal. y is a real or complex vector or matrix.

X = 0:0.01:1;
B = [1];
A = [1, 1, 1];
Y = filter_zerophase(B, A, X)

Where This Node Can Run:

Desktop OS: Windows

FPGA: This product does not support FPGA devices