Plotting multiple text files columns in the same graph

Hi guys, I have about 25 files consisting of 300 rows and 3 columns.

I'd like to plot the first column of each file in the same graph. Is it possible?

Thanks in advance !

[Ced]

Yes. Matlab help is your friend.

http://www.mathworks.com/help/matlab/import_export/ways-to-import-text-files.html http://www.mathworks.com/help/matlab/ref/plot.html?searchHighlight=plot

[Gabriel Maya]

Hi Ced: here is the code I got so far:

workDir='C:\Users\gabri\Desktop\Nova_pasta\Arquivos_Saida_Imex';

for i=1:25
cd(workDir);
 pasta= ['cd  ' num2str(i) ];
 eval (pasta)
filename=   '' workDir ''\'' num2str(i) ''\''arqanepi.rwo''
delimiter = '\t';
startRow = 6;

formatSpec = '%f%f%f%f%[^\n\r]';

%%Open the text file.

fileID = fopen('arqanepi.rwo','r');

dataArray = textscan(fileID, formatSpec, 'Delimiter', delimiter, 'HeaderLines' ,startRow-1, 'ReturnOnError', false);

%%Close the text file.

fclose(fileID);

%%Allocate imported array to column variable names

days(:,i) = dataArray{:, 1};

Oil(:,i) = dataArray{:, 2};

Gas(:,i) = dataArray{:, 3};

Water(:,i)= dataArray{:, 4};

   cd (workDir)

end

plot(days(:,1), Oil(:,:))

I am able to save all my data in the Variables day, oil, water and gas.

But when I try to plot all curves of Oil, for example, I only get one.

Can you help me with this?

Best Regards.

[Stephen23]

@Gabriel Maya: don't use cd to switch between files: this is slow and buggy. It is much more faster and more reliable to pass full/relative filepaths to your file handling functions, exactly as Walter Roberson shows in their answer. Also you should avoid using eval for such trivial code, which is also slow and buggy way to program.

Answer 1

[Walter Roberson]

workDir = 'C:\Users\gabri\Desktop\Nova_pasta\Arquivos_Saida_Imex';

delimiter = '\t';
startRow = 6;

%your description says three columns, your code says four, your previous format implied their might be more

formatSpec = '%f%f%f%f';

for i = 1:25
  this_subdir = sprintf('%d', i);
  filename = fullfile( workDir, this_subdir, 'arqanepi.rwo');

    %%Open the text file.

    fileID = fopen(filename, 'rt');

    dataArray = textscan(fileID, formatSpec, 'Delimiter', delimiter, 'HeaderLines', startRow-1, 'ReturnOnError', false);

    %%Close the text file.

    fclose(fileID);

    %%Allocate imported array to column variable names

    days(:,i) = dataArray{:, 1};

    Oil(:,i) = dataArray{:, 2};

    Gas(:,i) = dataArray{:, 3};

    Water(:,i)= dataArray{:, 4};

end

plot(days(:,1), Oil)

[Ced]

Did that answer your question? Otherwise, attach one of your files.

PS: If you want to have a legend for all files without having to type it up, you could do something like

N_files = 25;
leg_str = cellfun(@(x)sprintf('dataset %i',x),num2cell(1:N_files),'UniformOutput',0);
legend(leg_str)

[Gabriel Maya]

That answered !

Thanks for the sugestion also :)