[email protected] (Peter K.) wrote in
news:[email protected]:

> Al Clark <[email protected]> writes:
>
>> Assuming a Window approach:
>>
>> If the length of the filter is 4i-1, that is 3,7,11,..... there will
be
>> 2i nonzero coefficients and 2i-1 zero coefficients. The sequence is
>> w0,0,w2,0,......w(4i-2)
>>
>> If the length of the filter is 4i+1, that is 5,9,13,..... there will
be
>> 2i nonzero coefficients and 2i+1 zero coefficients. The sequence is 0,
>> w1, 0, w3,....0
>>
>> There is the same number of non zero coefficients for 4i-1 and 4i+1
>> length filters.
>
> I don't see why the 4i-1 length filter has different coefficients from
> the 4i+1 case.
>
> Is it the window that has zeros? (Hmm. w0, w2 etc suggests that.)
>
> Ciao,
>
> Peter K.
>

They are different and the "longer" filter gives better results, at least
near fs/4 where these filters are best. In my case I need a hilbert pair
in a region not too far from fs/4 so I get very good results with a short
filter.

I just don't understand the difference.

--
Al Clark
Danville Signal Processing, Inc.
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