In message
<CALBs-ThuY6qLHD4J3RdQsTdd9YP+1YphDpTzvxun4yTU9wM4DQ@...>,
dated Mon, 16 Dec 2013, Andy <Andrew.Ingraham@...> writes:
John Woodgate wrote:
To get x Hz resolution, you should, in practice, simulate for 2/x
seconds.
Actually, x Hz resolution needs only 1/x seconds.
See 'in practice', words you use yourself in the critique below.
Simulating for 2/x seconds gives you x/2 Hz resolution, which in
practice might be useful if you know you have discrete frequency
components at x Hz increments. ?Having those in-between components in
the FFT plot both makes it easier to see the components, and can be
used as a rough gauge of the FFT's accuracy. ?If components which
should be very low, are not low, then something is wrong and you need
to take a closer look
I put the factor of 2 in and the words 'in practice' for precisely the
reasons you have cited again, as you did in your previous message. We
are in violent agreement but I fear that a thirst for rigor can result
in added confusion.
--
OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk
Nondum ex silvis sumus
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
