Signal Processing Toolbox

filter

Filter data with a recursive (IIR) or nonrecursive (FIR) filter

filter is a MATLAB function.

Signal-specific Information

Filter Method of DFILT

Filter is also an overloaded method of the discrete-time filter object (dfilt). You can pass an object handle, data, and initial conditions into the filter method. Note, however, that the recommended method of passing initial conditions into a dfilt is by using the states method. For more information, see the dfilt reference page.

Filter Normalization

Using filter on b and a coefficients normalizes the filter by forcing the a0 coefficient to be equal to 1.

Using the filter method on a dfilt object does not normalize the a0 coefficient.

fftshift

filter2