modify a data file using MATLAB?
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Hi guys,
I am a beginner of MATLAB. Now I have a series of data files output from Openfoam, in terms of different time step (shown in floowing figure). A
and under each folder I have the data included in the file like below. However I only need the column of x and p for each file.
I would like to integrate the files in one separate file and add a second colum between x and p, by t (t=0.5, 1, 1.5 ....)., shown in following format. I have no experience of modyfing a file. Could you please give me some tips, thanks a lot.
%x t value
0 0.5 3000
1 0.5 3200
...
20 30 3690
采纳的回答
Mathieu NOE
2021-6-28
so this is it !
hope it helps
see the attached file too - you will need them to have the folders sorted in natural order , which is not what matlab does "naturally" , so to say
main code :
clc
clearvars
S = dir('**/*.raw');
[m,n] = size(S);
%% first we have to sort the folders in natural order - otherwise the time steps
% will not be uniformly increasing
for ci = 1:m
folders{ci} = S(ci).folder;
filenames{ci} = S(ci).name;
end
[folders_sort,ndx,dbg] = natsort(folders);
filenames_sort = filenames(ndx);
%% main loop for data extraction and concatenation
outdata = [];
for k = 1:m
foldername = char(folders_sort(k)) % display in command window the folder name
filename = char(filenames_sort(k)) % display in command window the file name
if strcmp(foldername(end-1:end),'\0')
% do nothing (skip t = 0 results)
else
F = fullfile(foldername, filename);
data = importdata(F, ' ', 2);
data = data.data;
[m,n] = size(data);
% get the simulation time step value from folder name
ind = strfind(foldername,'\');
time_step = str2num(foldername(ind(end)+1:end));
tmp = [data(:,1) time_step*ones(m,1) data(:,4)];
% now vertical concatenation of all files data
outdata = [outdata ; tmp];
end
end
%% export data
T = array2table(outdata);
T.Properties.VariableNames(1:3) = {'%x','t','p'} % %x t p
writetable(T,'file1.csv')
7 个评论
kimy
2021-6-28
Mathieu NOE
2021-6-28
You're welcome
kimy
2021-7-15
Mathieu NOE
2021-7-15
yes - what's the issue ?
kimy
2021-7-19
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