How do I omit a range of points from line?

% MATLAB Code

function [dMean, dMax, dMin] = EMGFilter6(EMG)

EMG_2 = EMG;

t = EMG_2(:,1); % time

x = EMG_2(:,2); % signal

d = abs(x);

windowSize = 1000;

b = (1/windowSize)*ones(1,windowSize);

a = 1;

dMean = mean(d);

dMax = max(d);

dMin = min(d);

j = 0.01*dMean;

p = 'concussion';

l = 'no concussion';

y = filter(b,a,d);

for k = i:y

plot(t,d,'color','r')

hold on

plot(t,y,'color','b')

legend('Input Data','Filtered Data')

end

for g = i:y

if g>j

disp(l)

elseif g<j

disp(p)

elseif g == j

disp(l)

end

end

end

% Hello, I'm given a data set of EMG signals. I created a running average mean line for the signal defined by variable "y". I want to omit a range of points from the beginning of the average mean line y so that my running average mean line doesn't start at zero.

Answer 1

[Voss]

I'm not sure if this is what you want, but here's how you can remove data before t = 1, for instance:

S = load('data.mat');

EMGFilter6(S.Trial1);

function [dMean, dMax, dMin] = EMGFilter6(EMG)
EMG_2 = EMG;
t = EMG_2(:,1); % time
x = EMG_2(:,2); % signal

% remove t and x before t = 1:
idx_to_remove = t < 1;
t(idx_to_remove) = [];
x(idx_to_remove) = [];

d = abs(x);
windowSize = 1000;
b = (1/windowSize)*ones(1,windowSize);
a = 1;
dMean = mean(d);
dMax = max(d);
dMin = min(d);
% j = 0.01*dMean;
% p = 'concussion';
% l = 'no concussion';
y = filter(b,a,d);
% for k = i:y

% plot(t,d,'color','r')
plot(EMG_2(:,1),abs(EMG_2(:,2)),'r') % plot the entire data

hold on
plot(t,y,'color','b')
legend('Input Data','Filtered Data')
% end
% for g = i:y
%         if g>j
%             disp(l)
%         elseif g<j
%             disp(p)
%         elseif g == j
%             disp(l)
%         end
% end
end

[Fue Xiong]

Sorry, I technically don't want to remove the values from the beginning of the line. I want to in a way be able to iterate through each value along that average mean line y, but skipping say the first 50 values at the beginning of the line. This is because what I am trying to do is detect a drop in the average mean line y when it crosses the threshold "j" in this case. But if the starting average mean line y always start at a value of 0, it will always present itself in the elseif case of "concussion".