Loop generation doubt.
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Martin Thomas
on 22 Aug 2020
Commented: the cyclist
on 23 Aug 2020
Hi,
I need to create a loop. I have to do a numerical analysis of thousands of data points.
My equation is,
E=A*cos(k-(w*t))
I have A,k and w three of them have same length 1x10. In the case of t which i have 1x50.
what i have to do is i need to take the first value of A,k and w and vary t (means run with range of values) . I need to do the same processs for the rest of the rows of A,k and w and vary t.
To be more precise.
A k w T
1 1 1 1
2 2 2 2
3 3 3 3
4 4 4 4
N N N 5
6
N
the equation will be
First calculation need to be
E=1*cos(1-(1*(1....N)))
second
E=2*cos(2-(2*(1....N)))
.......
continue upto length of A,k,w
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Accepted Answer
the cyclist
on 22 Aug 2020
% DO NOT USE THESE. USE YOUR DATA. THESE ARE FOR AN EXAMPLE ONLY
T = rand(160547,1);
A = rand(44880,1);
k = rand(size(A));
w = rand(size(A));
%%%%%% Only use the code below %%%%%
% Preallocate memory for E
E = zeros(1,160547);
% Calculate E
for ii = 1:size(E2,2)
E(ii) = sum(A.*cos(k-(w.*T(ii))));
end
11 Comments
the cyclist
on 23 Aug 2020
I don't really use fft. I would open a new question, and upload an image of the plot using INSERT again, along with the code that generates it.
Try to be very clear about your exact question.
More Answers (1)
the cyclist
on 22 Aug 2020
Edited: the cyclist
on 22 Aug 2020
You don't need to use a loop. MATLAB will do vectorized calculations.
If you have a fairly recent version of MATLAB, you can do this using implicit expansion of the vectors:
% Make up some data
A = rand(1,10);
k = rand(1,10);
w = rand(1,10);
t = rand(1,50);
% Calculate E
E = A.*cos(k-(w.*t'));
The output E will be 50x10.
Note that I took the transpose of t, and also used element-wise multiplication and not matrix multiplication. You can read about the difference here.
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