what is the correct formula of (sum of ...from...to...) in matlab

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Good mind
Good mind 2017-4-27
评论： Good mind 2017-4-30
snrin=(-5:5:55); %initial snr
N=length(ecg); % length of ecg signal
n=(0:N-1);
e=sum (ecg^2) from 0 to N-1; **% I want to write this formula correctly**
f=sum (W^2) from 0 to N-1; *% also this*
A=sqrt(e/(10^(snrin/10))*f); *% also this one*
  2 个评论
James Tursa
James Tursa 2017-4-27
How is the indexing from 0 to N-1 related to the variable "ecg"? I.e., what would an index of 0 mean? Same question for the other sums.
Good mind
Good mind 2017-4-27
ECG is a signal sampled with 360hz. 0 to N-1 i.e means along the length of ecg signal

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Walter Roberson
Walter Roberson 2017-4-27
e = sum( ecg(1+n).^2 );
f = sum( W(1+n).^2 );
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Walter Roberson
Walter Roberson 2017-4-30
ecgnoisy = repmat(ecg(:), 1, length(A)) + repmat(W(:), 1, length(A)) .* repmat(A, numel(W), 1);

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