This is machine translation

Translated by Microsoft
Mouseover text to see original. Click the button below to return to the English verison of the page.

Note: This page has been translated by MathWorks. Please click here
To view all translated materals including this page, select Japan from the country navigator on the bottom of this page.


Discrete-time, direct-form, FIR filter


Hd = dfilt.dffir(b)
Hd = dfilt.dffir


Hd = dfilt.dffir(b) returns a discrete-time, direct-form finite impulse response (FIR) filter, Hd, with numerator coefficients, b.

Hd = dfilt.dffir returns a default, discrete-time, direct-form FIR filter, Hd, with b=1. This filter passes the input through to the output unchanged.

The resulting filter states column vector is



Create a direct-form FIR discrete-time filter with coefficients from a 30th order lowpass equiripple design:

b = firpm(30,[0 .1 .2 .5]*2,[1 1 0 0]);
Hd = dfilt.dffir(b)

Introduced before R2006a

Was this topic helpful?