load and do operations on multiple file in a loop

Hi,

I have my files named 'Us2asp_001.txt', 'Us2asp_002.txt, .......'Us2asp_00n.txt'.

I want to read the files and do similar operations in each of them.

I read about it and got to know that sprintf is a solution. However, the files are saved into a cell array and I am not sure how to do the further calculations.

I am rather new to matlab. Can you please help me with this?

I have attached the code which I want to write in a loop.

Thank you in advance.

Regards

Dipen

data1=readtable('Upasp2_001.txt');
data2=readtable('Upasp2_002.txt');
data3=readtable('Upasp2_003.txt');

%% Changing units
data1{:,2:end}=data1{:,2:end}*-1000;
data2{:,2:end}=data2{:,2:end}*-1000;
data3{:,2:end}=data3{:,2:end}*-1000;

%% Calculation
data1{:,7}=data1{:,3}+data1{:,5};
data1{:,8}=data1{:,4}+data1{:,6};
data1{:,9}=sqrt(data1{:,7}.^2+data1{:,8}.^2);
data1.Properties.VariableNames([7 8 9])={'Px','Py','Ptot'};

data2{:,7}=data2{:,3}+data2{:,5};
data2{:,8}=data2{:,4}+data2{:,6};
data2{:,9}=sqrt(data2{:,7}.^2+data2{:,8}.^2);
data2.Properties.VariableNames([7 8 9])={'Px','Py','Ptot'};

data3{:,7}=data3{:,3}+data3{:,5};
data3{:,8}=data3{:,4}+data3{:,6};
data3{:,9}=sqrt(data3{:,7}.^2+data3{:,8}.^2);
data3.Properties.VariableNames([7 8 9])={'Px','Py','Ptot'};

%% Plotting

figure
plot(data1.uxtop,data1.Ptot,data2.uxtop,data2.Ptot,data3.uxtop,data3.Ptot);

legend('Mesh 1','Mesh2','Mesh3');
title('Load displacement');
xlabel('ux (mm)');
ylabel('Total Load applied (P) kN');
xlim([0,10]);

Answer 1

[Luna]

Hi Dipen,

As far as I understand you want to read all the files in a specific folder with a for loop and do the calculations.

I wrote some code for you, you can check if it works correctly.

(Please don't forget to read comments.)

%% this part gives you the txt file name list in your folder
dirName = 'C:\Users\....\Desktop\NewFolder';   % folder path (please edit this as your own)
files = dir( fullfile(dirName,'*.txt') );   % list of all *.txt files
files = {files.name}';                   % file names

%pre allocation for legend for the plot
legendString = cell(1,numel(files));
%% for loop
for i = 1:numel(files) % for loop for each file
    % readtable
    data = readtable(files{i});
    % changing units
    data{:,2:end}=data{:,2:end}*-1000;
    % Calculation
    data{:,7}=data{:,3}+data{:,5};
    data{:,8}=data{:,4}+data{:,6};
    data{:,9}=sqrt(data{:,7}.^2+data{:,8}.^2);
    data.Properties.VariableNames([7 8 9])={'Px','Py','Ptot'};
    % plot
    figure;
    plot(data.uxtop,data.Ptot); % plots the ith file data 
    hold on; % holds the plot for the next loop
    legendString{i} = ['Mesh',sprintf('%d',i)]; % creates legend string as MeshX where X is a number
end % end for loop

%% legend,title,axis properties for plotted figure
legend(legendString);
title('Load displacement');
xlabel('ux (mm)');
ylabel('Total Load applied (P) kN');
xlim([0,10]);

ps. If you want to shorten your calculations section, please share an example data(txt) and desired output.

[Dipen Bista]

Hi Luna,

It works perfectly.

Thank you very much :).

Attached files

where calculation is to be performed.

• Upasp2_001.txt
• Upasp2_002.txt

The plot of 'uxtotal' vs 'Ptot' from these files should be compared to

plot of 'uxtotal' vs 'Ptot' from the 'labtotal.txt'

Best Regards,

Dipen

[Luna]

your welcome :)

Answer 2

[madhan ravi]

Lookup cell2mat() , horzcat() , vertcat() and cellfun() to work with cells.

[Dipen Bista]

Hi Madhan Ravi

Thank you for the answer.

My matlab skills are not that good.

Could you please write how would you wirte the code in matrix for the above problem I worte if you would have done it?

Best Regards,

Dipen