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Topic: sum of exponentials
Replies: 9   Last Post: Nov 24, 2012 7:16 PM

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Roger Stafford

Posts: 5,867
Registered: 12/7/04
Re: sum of exponentials
Posted: Nov 22, 2012 1:19 PM
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"dwi" wrote in message <k8l6sb$2fj$1@newscl01ah.mathworks.com>...
> I have a matrix whose data are interrupted by sequences of zeros. I need every time that there's a zero value to substitute it with a sum of exponentials using the previous data, eg:
> x=[x1 x2 x3 0 0 0 x7 0 0]
> When i find the first zero in the element x4 I want:
> x4=(x3*e^(-1)+x2*e^(-2)+x1*e^(-3))/(e^(-1)+e^(-2)+e^(-3));
> However, when I find the second zero value I need to calculate the same expression but without using the previous recalculated values. That is,
> x4=x5=x6
> and for x8 I will use only the values in x7,x3,x2,x1 and then x8=x9 etc
> And all this for a 180000-length data.
> Any ideas on how to do this?
> Thanks in advance

- - - - - - - - -
a = 0; b = 0;
for k = 1:length(x)
if x(k) ~= 0
a = x(k) + a*e^(-1);
b = 1 + b*e^(-1);
else
x(k) = a/b;
end
end

Roger Stafford



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