Creating 2 new arrays for given condition

Good day, I'm trying to write an algorithm that goes as follows:

So I have y values (y) and corresponding time values (tTrans). I want to make new arrays with one of them being y values only greater than 0.0004 and another with it's corresponding time values. however I keep getting the error:

Please help and thanks in advance!

#######################################################

Array indices must be positive integers or logical

values.

Error in Practical1 (line 74)

yn(i)=yT(r(i));

#######################################################

Let y be a [n,1] size array

let tTrans be a [1,n] size array

########################################CODE##########################################

for i=1:length(y)

if abs(yT(i))>0.0004

n=n+1; % Get the array posistions where y>0.001 for speech, creating n, which is the size of my second arrays.

end

end

r = zeros(1,n);

yn= zeros(1,n); %Initializing sizes of my second arrays

tT= zeros(1,n);

for i=1:n

if abs(yT(i))>0.0004;

for j=1:n

r(j)=i; % Get the array posistions where y>0.001

end

end

end

pause;

for i=0:n

yn(i)=yT(r(i)); %Wanting to create a new array, with all the y-values greater than 0.004;

tT(i)=tTrans(r(i)); %Wanting to create a new array, for the time values corresponding to values greater than 0.004;

end

yn=transpose(yn);

hold off;

plot(tT,yn);

Answer 1

[the cyclist]

keepIndex = y>0.0004;
y_new = y(keepIndex);
tTrans_new = tTrans(keepIndex)

[Leon Ellis]

Thank you very much! You're a life saver