Code for extracting the special values

Hi all,

I have txt file which contains two columns: the first column is time [hourly resolution], and the second column is the answer of my function (values). I want to extract the values from the second column which are based on daily [I mean 0,1,2,3,...]. and then write it in another txt file, which will have two columns and be like: 0 814 1 745 2 660 3 539 . .

How should I have to write my code? Attached my .txt file here.

I appreciate any help and thanks in advance. Hope to hear from you. Sepideh

Answer 1

[Stephen23]

% Read original data file:
M = dlmread('remaining particles total.txt','\t');
H = min(M(:,1)):max(M(:,1));
[X,Y] = ismember(H,M(:,1));
assert(all(X),'Some hour values are missing')
% Write new data file:
fid = fopen('newfile.txt','wt');
fprintf(fid,'%d\t%d\n',M(Y,:).');
fclose(fid);

This creates the following new text file:

0  814
1  745
2  660
3  539
4  420
5  355
6  303
... lots here
1821  0
1822  0
1823  0
1824  0
1825  0

[SEPIDEH]

Great,

Thanks a lot for the help. Another tricky question: if I have again another text file: first column showing time [hrly resolution], and the second column the function value. Then if I want to extract every 6hrs, which means 0,6,12,18,24,30,...

Then which part of the code should I modify to have the preferred results? I attached another text file.

Hope to hear from you. Best regards, Sepideh

[Stephen23]

You just need to define the variable H to be a vector of time values that you want to keep. You could simply do this:

H = 0:6:max(M(:,1));

If my answer helped you, then please consider accepting it.

[SEPIDEH]

Hi,

I modified line number 5 and I got error in below:

Error using sixhrs (line 5) Some hour values are missing

So, could you kindly let me know where is the problem, please?

Hope to hear from you. Best Sepideh

[SEPIDEH]

ok,

let me explain another time. I attached text file and the Matlab code which I modified here. If you run the code you will see the above error, which I mentioned.

Therefore, How is it possible to solve this problem? Hope to hear from you Thanks in advance for help Sepideh