Zitat von Christof Ressi <i...@christofressi.com>:
That's only half the story. Generally, one shouldn't expect floating
point computations to yield the exact same result with different
compilers/machines. The rounding errors themselves are very small,
but they can accumulate over long periods of time or get amplified
by recursive algorithms.
I've made an alternative implementation [biquad2~] that uses direct
form 1. It shows significantly less noise than the [biquad~]
examples. See attachments.
That's right what you wrote.
However, what worries me is that if I run a Pd vanilla patch on
different Pd versions (i386 or amd64) with the same floating point
precision, I expect the same results.
e.g. the test patch running on Pd-0.52-1-xxx-i386 produces -60dB low
frequency spikes, the identical patch running on Pd-0.52-1-xxx-amd64
produces -34dB high frequency bursts. And that's a realistic simple
situation, a microphone signal feeds a 3rd order high pass filter.
Thomas Musil
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