Averaging minute data to hour data

Greetings all.

My name is Joseph Moses.

I would like this great house to help me on how to average my data into hour and the hourly averaged data into daily.

For instance,

1.How do i get the corresponding average of 0.00:0.983, 1.000:1.983 till 23.00:23.983 in the second column (VTEC Data) from the below data or the attached.

2. Then plot the result Time against VTEC

[Ameer Hamza]

No need to include the complete txt file in the question. I have deleted to make the question readable.

Answer 1

[Star Strider]

Try this:

D = load('bjcoo001-2015-01-01.txt');
M = ceil(D(:,1)+1E-4);
HrMeans = accumarray(M, (1:numel(M)).', [], @(x){mean(D(x,2:4))});
Result = [(0:23).' cell2mat(HrMeans)]

figure
plot(Result(:,1), Result(:,2))
grid
xlabel('Time')
ylabel('VTEC')

producing:

Result =
         0   10.8497    2.0272    6.3800
    1.0000    8.4937    1.8062    6.3800
    2.0000    7.6810    1.1152    6.3800
    3.0000    6.0948    1.0160    6.3800
    4.0000    3.7198    1.0692    6.3800
    5.0000    3.0660    1.1472    6.3800
    6.0000    8.8583    0.9718    6.3800
    7.0000   18.5332    1.1425    6.3800
    8.0000   26.3258    1.4597    6.3800
    9.0000   32.8312    1.5363    6.3800
   10.0000   39.3363    1.9443    6.3800
   11.0000   45.3585    3.1638    6.3800
   12.0000   49.2812    3.2907    6.3800
   13.0000   51.2610    2.2868    6.3800
   14.0000   53.3373    2.2015    6.3800
   15.0000   49.9703    4.1498    6.3800
   16.0000   45.2548    3.5810    6.3800
   17.0000   37.1800    3.4638    6.3800
   18.0000   24.5763    3.7843    6.3800
   19.0000   16.1022    4.9532    6.3800
   20.0000   14.7298    3.7925    6.3800
   21.0000   14.8348    4.0482    6.3800
   22.0000   13.5453    3.9738    6.3800
   23.0000   14.4595    5.1812    6.3800

EDIT —

Added plot image —

[Moses Joseph]

It works correctly. You woudn't know what graet thing you have done for me. I have been on this for over 3 weeks now.

I am deeply grateful sir. Thank you a whole lot.

But please can you help me with the folowing:

1. Kindly explain the code to me

2. What if I want to do same for 365 files of such data automatically?

3. Then how do I do daily, weekly and mothly, quarterly avearge for the 365 days data files?

If you don't mind I send the files via your mail address sir. mine is [e-mail]

Thank you sir

[Star Strider]

As always, my pleasure!

(1.) The ‘M’ variable creates the individual hour designations as a vector of integers. The accumarray call then uses that vector and a vector of the linear indices (the second argument), to create a cell array using the anonymous function in the fourth argument (that takes the means of the matching columns 2 through 4). (The accumarray function is a very efficient set of loops.) It returns those mean values as a cell array. The ‘Result’ variable then presents those values (along with a synthesized hour vector in the first column).

(2.) Put my code in a loop that reads and processes each file, then save ‘Result’ as a cell array (easiest) for each file. See: Import or Export a Sequence of Files for hellp with that. The index of the cell array would correspond to the day.

(3.) I am not certain what you want to do. It would likely be best to simply use a loop, indexing it appropriately to get the result you want.

[Moses Joseph]

Greetings.

Once again, thank you for the previous help.

I still can't work out the the solution you gave for export.

But maybe from the question I am about to ask will enable solve part of question 3.

What if I have 5 or more txt files ranging from bjcoo001-2015-01-01.txt 2015-01-05.txt, how do I achieve the same result as the above for each of the 5 files?

Thank you for your usual assistance sir

[Star Strider]

As always, my pleasure.

I would do something like this to read them:

numFiles = 5;
for k = 1:numFiles
    filename = sprintf('bjcoo001-2015-01-%02d.txt', k)
    D = load(filename);
    M = ceil(D(:,1)+1E-4);
    HrMeans = accumarray(M, (1:numel(M)).', [], @(x){mean(D(x,2:4))});
    Result{k} = [(0:23).' cell2mat(HrMeans)]
end

and similarly for saving the ‘Result’ cell array to new files.

To write them in a similar loop, consider using writecell for this, although other options are possible. Also consider using fullfile to be certain the files are written to the directory where you want to put them (and also from where you want to read them).

I can’t test this because I don’t have the files. However since it uses my existing code and only creates the individual file names (and that appears to work correctly), it should work.

[Moses Joseph]

Thank you very much sir.

[Star Strider]

As always, my pleasure!

Answer 2

[Ameer Hamza]

Try this

M = readmatrix('bjcoo001-2015-01-01.txt');
time = t(:,1);
hours = floor(time);
hour_average = splitapply(@(x) mean(x(:, 2:end), 1), M, hours+1);
hour_average = [unique(hours) hour_average];

plot(hour_average(:,1), hour_average(:,2:4));

[Moses Joseph]

Thank you very much on this but I am getting Undefined function or variable 'readmatrix'. How do I defined it again since it was already defned?

[Ameer Hamza]

I guess you are using a release older than R2019a. readmatrix was added in R2019a.