On 12/10/12 11:18 AM, Bjorn Roche wrote:
On Dec 10, 2012, at 4:41 AM, Alessandro Saccoia wrote:
I don't think you have been clear about what you are trying to achieve.
Are you trying to compute the sum of many signals for each time point? Or are
you trying to compute the running sum of a single signal over many time points?
Hello, thanks for helping. I want to sum prerecorded signals progressively.
Each time a new recording is added to the system, this signal is added to the
running mix and then discarded so the original source gets lost.
At each instant it should be possible to retrieve the mix run till that moment.
I see. I think you'll want to go with my first suggestion:
1
Y = ---- * ( X + X + ..... X )
N 1 2 N
But only do the division when you "retrieve". In other words, store NY:
NY = ( X + X + ..... X )
1 2 N
just a quick note, Bjorn. consider viewing your ASCII math with a
fixed-width font. we cannot all guess at what proportional-width font
you might have been using, but if everyone uses a fixed-width font (for
ASCII math or ASCII art), characters line up and you can read the
symbols. i use a combination of TeX-like constructs (like X_0, X_1, or
y^2, etc) and positioning (like i don't like to use the LaTeX construct
for a summation or integral for ASCII math). also i use uppercase for
either transformed (freq domain) signals or important constants (like
N). so i might express your first equation like:
N
y = 1/N SUM{ x_i }
i=0
or
N
y[n] = 1/N SUM{ x_i[n] }
i=0
--
r b-j r...@audioimagination.com
"Imagination is more important than knowledge."
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