Import and reshape the data

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Brave A
Brave A on 5 Sep 2022
Commented: Walter Roberson on 6 Sep 2022
I have 20000 data(in attachment) and data is in groups of 10 -- the data starts at 0 and returns to 0 each 10 entries.
I needs to plot them so I tried
readmatrix('trans_bad.txt', 'delimiter', '\t');
but it's not working. so I tried this one
r3 = importdata('trans_bad.txt');
ro = mean(reshape(r3,40,[]), 1);
ro = ro';
ys_03 =ro(1:max_iterations, 1);
plot(xs, ys_03);
not sure if my way is correct because the curve dropped into 0. Any suggestions?
thanks in advance!

Accepted Answer

Image Analyst
Image Analyst on 5 Sep 2022
Looks like it's 0 every 20 elements, not 10.
Try this:
data = importdata('trans_bad.txt');
% Reshape into 20 by 1000 matrix.
data2 = reshape(data', 20, [])
data2 = 20×1000
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 3 4 3 2 3 2 2 3 2 3 3 2 3 3 3 3 2 2 2 3 2 2 2 2 2 2 2 2 2 11 10 12 8 7 9 7 7 9 7 8 9 6 8 9 8 8 7 7 6 8 6 7 6 7 7 6 6 7 5 22 21 23 15 15 18 15 14 17 14 16 17 13 16 18 14 15 15 14 12 15 12 13 12 14 14 12 12 15 10 35 34 37 24 26 29 25 23 28 24 26 28 22 26 29 22 25 25 23 20 24 19 21 20 23 24 20 20 25 17 51 50 53 36 40 41 37 34 41 36 38 41 33 38 42 31 36 37 34 30 34 28 31 30 33 36 29 29 38 26 69 69 71 49 56 55 51 47 56 51 51 55 46 52 56 41 50 50 46 42 46 38 43 41 45 50 40 40 52 36 89 90 92 64 75 71 67 62 72 68 66 71 60 68 72 52 66 64 60 55 59 50 56 53 58 65 52 52 68 48 112 113 115 81 96 89 84 78 90 87 83 89 76 85 90 65 83 80 75 70 73 63 71 66 72 82 66 65 85 61 137 138 139 100 119 108 103 96 110 108 101 108 93 104 109 79 102 97 92 86 88 77 87 80 87 100 81 79 103 76
[rows, columns] = size(data2)
rows = 20
columns = 1000
for row = 1 : rows
plot(data2(row, :), '-');
hold on;
end
grid on;
  15 Comments
Image Analyst
Image Analyst on 6 Sep 2022
I tried this:
data = importdata('trans_bad.txt');
% Reshape into 20 by 1000 matrix.
data2 = reshape(data', 20, [])
data2 = 20×1000
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 3 4 3 2 3 2 2 3 2 3 3 2 3 3 3 3 2 2 2 3 2 2 2 2 2 2 2 2 2 11 10 12 8 7 9 7 7 9 7 8 9 6 8 9 8 8 7 7 6 8 6 7 6 7 7 6 6 7 5 22 21 23 15 15 18 15 14 17 14 16 17 13 16 18 14 15 15 14 12 15 12 13 12 14 14 12 12 15 10 35 34 37 24 26 29 25 23 28 24 26 28 22 26 29 22 25 25 23 20 24 19 21 20 23 24 20 20 25 17 51 50 53 36 40 41 37 34 41 36 38 41 33 38 42 31 36 37 34 30 34 28 31 30 33 36 29 29 38 26 69 69 71 49 56 55 51 47 56 51 51 55 46 52 56 41 50 50 46 42 46 38 43 41 45 50 40 40 52 36 89 90 92 64 75 71 67 62 72 68 66 71 60 68 72 52 66 64 60 55 59 50 56 53 58 65 52 52 68 48 112 113 115 81 96 89 84 78 90 87 83 89 76 85 90 65 83 80 75 70 73 63 71 66 72 82 66 65 85 61 137 138 139 100 119 108 103 96 110 108 101 108 93 104 109 79 102 97 92 86 88 77 87 80 87 100 81 79 103 76
[rows, columns] = size(data2)
rows = 20
columns = 1000
means = mean(data2, 1);
plot(means, 'b-', 'LineWidth', 2);
grid on;
What, exactly, is wrong with that? I know it doesn't match the picture you posted, but the picture you posted does not match what you're saying in words using the data you provided.
Walter Roberson
Walter Roberson on 6 Sep 2022
Is there any other command instead of reshaping like taking windows size?
Yes, you could use blkproc() to request to process 20 (or 40) samples at a time. The function is intended primarily for image processing, but there is no inherent reason why you could not use it for other block operations.
However, really if reshape() and mean() is not serving your needs, then I really doubt that blkproc() would be any more satisfactory, and using it would tend to obscure what you are doing. At this point I would suggest you use a for loop, like
for idx = 1 : 20 : numel(data)-19
thissegment = data(idx:idx+19);
%do something appropriate with the data in thissegment
end
This will provide clarity to you that the problem is not reshape() but rather a problem with your data or with your expectations.

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