finding an closest possible element in an 7 dimensional matrix array

Hi,

Code is as follows

time = period_fun(2,2,1,10,10,15,3) is a 7D matrix with has domensions 2*7*1*10*10*15*8
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

So when hardcode the time = 26.601 and pass it.

I am trying to find the closest value possible in period_arr

%finding the closest element possible  to time = 26.601
dist = abs(period_fun -  time);
min_dist = min(dist(:));
idx = find(dist == min_dist );
disp(period_arr(idx))

The output comes as 26.601, which is wrong.

My array has a value 26.801 which is closer to 26.601 it is not able to pick that value.

How can i precisely tune it ? so that i can make it more robust for even 0.001 variation

Please help me out

[Ameer Hamza]

If this line

disp(period_arr(idx))

displays 26.601, then it indicates that your matrix does have an element with value 26.601. I don't think there is any other explanation here.

Also, this line shoule be

min_dist = min(dist(:));

[Ganesh Kini]

min_dist = min (dist (:));

I tried with this too.

My matrix does not have 26,601 as the value. I just gave a random number with decimals to check the precision. I have tried for 4-5 examples its not working

It is not able to trace the nearest value possible

Please suggest

[Ameer Hamza]

Can you attach the data in your array period_arr?

[Ganesh Kini]

PFA for the elements in period_arr

Answer 1

[Ameer Hamza]

A matrix with dimensions [2 7 1 10 10 15 8], will have 168000 elements. The file you shared only have 166379 elements. I cannot create the matrix with a specified dimension. If I suggest a solution, you may still not find that it is not working. However, I have given a solution by padding array with zeros to make its size equal to 168000.

fid = fopen('Mat file.txt');
data = textscan(fid, '%f', 'HeaderLines', 6);
period_arr = data{1};
fclose(fid);

period_arr = padarray(period_arr, 168000 - numel(period_arr), 0, 'post');
period_arr = reshape(period_arr, [2 7 1 10 10 15 8]);

time = 26.601;

dist = abs(period_arr -  time);
[min_dist, idx] = min(dist(:));
disp(period_arr(idx))

When I run this code, it get the value

26.602

Which is closest value to 26.601.

26.801 is not the closest value in this array.

[Ganesh Kini]

Hi Ameer,

Thanks for the suggestion i have an issue.

1 ´ = 2.3

t2 = 5.6

% its is a 2 * 7 * 1 * 10 * 10 * 15 * 8 matrix

p = period_arr (1,:,:,:,:,:, :); % this is of the form p = period_arr (p1, p2, p3, p4, p5, p6, p7);

n = period_arr (2,:,:,:,:,:, :); % this is of the form n = period_arr (n1, n2, n3, n4, n5, n6, n7);

dist_p = abs (p - t1);

[min_dist_p, idx_p] = min (dist_p (:));

dist_n = abs (n - t2);

[min_dist_n, idx_n] = min (dist_n (:));

c_tp = p (idx_p);

c_tn = n (idx_n);

So based on the minimum distance i get the closest value, and it is working fine.

But, I have a problem here I have to get only the closest value where the indices p4 = n4 and p5 = n5. It should regulate the same value for both p and n.

How do i do that? please help me out. I am stuck in this problem from 2 days

For example

I can have

2.6 = period_arr (1,:,:, a, b,:, :)

7.8 = period_arr (2,:,:, a, b,:, :)

Answer 2

[Image Analyst]

If you have the Statistics and Machine Learning Toolbox, try knnsearch(). I think you can have every point be a new class. It will tell you which point is closest to your query point.