Read and plot .txt file (into .mat)

Question

I need to read test.TXT file(tab delimited) into MATLAB.

TXT file have form:

Datum Time Data1 Data2 Data3 Data4 Data5
06/28/2012 09:27,3 1,931764 -0,008698 4,151306 33,865424 -44,923096
06/28/2012 09:27,3 1,931764 -0,003662 4,154358 33,865424 -44,831543
06/28/2012 09:27,4 1,928712 -0,001526 4,168701 33,866102 -45,472412
.....................................................

After that I need to plot these data (for example time vs. data1; time vs. data2..)

What is the easiest way to open and read test.txt file so I can then plot my data (insert all data to workspace..). I tried to import data, but then MATLAB import data as one column. :/

Thanks

EDIT

I just noticed that I copy wrong format of time into first post :S

Datum Time Data1 Data2 Data3 Data4 Data5
06/28/2012 17:09:27,3 1,931764 -0,008698 4,151306 33,865424 -44,923096
06/28/2012 17:09:27,3 1,931764 -0,003662 4,154358 33,865424 -44,831543
06/28/2012 17:09:27,4 1,928712 -0,001526 4,168701 33,866102 -45,472412
.....................................................

17:09:27,4 -> 17(hour), 09 (minutes), 27 (seconds), 4(miliseconds)

Here is now big problem with , and .

Community · Accepted Answer · 2017-05-23 12:04:43Z

2

As answered previously in this question you should use either textscan or fscanf

After taking a closer look there are a few interesting nuances to your question. The solution I went with was to preserve the columnar structure by reading everything as a string. That helps to keep everything ordered while commas are replaced with periods, date strings are processed to datenums and finally the numbers stored as strings are converted.

fid = fopen('test.txt','rt');
header = textscan(fid,'%s %s %s %s %s %s %s',1); 
data = textscan(fid,'%s %s %s %s %s %s %s');
data = cellfun(@(x) strrep(x,',','.'),data,'UniformOutput',false);
clean_data(:,1) = arrayfun(@(x) datenum([data{1}{x} ' ' data{2}{x}]), 1:length(data{1}) )';
clean_data(:,2:6) = cell2mat(cellfun(@str2num , [data{3:end}],'UniformOutput',false));
fclose(fid);

There are a few messy transitions in there. But the general approach should be solid so long as your files are not outrageously long. Here are the results:

>> datestr(clean_data(:,1))
ans =
28-Jun-2012 09:27:18
28-Jun-2012 09:27:18
28-Jun-2012 09:27:24

>> clean_data(:,2:end)
ans =
1.9318   -0.0087    4.1513   33.8654  -44.9231
1.9318   -0.0037    4.1544   33.8654  -44.8315
1.9287   -0.0015    4.1687   33.8661  -45.4724

And finally to plot versus date, which was the original goal:

>> plot(clean_data(:,1),clean_data(:,2))
>> datetick

edited May 23, 2017 at 12:04

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answered Jun 30, 2012 at 13:03

Salain

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13 Comments

Alex Knok Over a year ago

Yes I tried already but it's nothing working. I know I must first change all , to . and after this read line after line; Tried with this but is not OK: fid=fopen('test.txt','rt'); while ~feof(fid) l=fgetl(fid) ; strrep(l,',','.'); end

Salain Over a year ago

I would use fid=fopen('test.txt'); s=textscan(fid,'%s','delimiter','\n'); s=strrep(s{1},',','.'); to load and remove commas, then probably sscanf to load from there, pulling the dates out as strings then using datevec to get them into a Matlab friendly format. I'll update my answer with a more complete solution in a second

Alex Knok Over a year ago

Hmm, thanks for idea; the bigger problem is after I read data into matlab.. I hope you will found solution, i will wait; Many thanks.

Alex Knok Over a year ago

thanks for this solution. But how can I now plot for example 3rd column. Plot(data(:,3), ??) I need to plot data vs time.

Salain Over a year ago

Hey Alex, actually I already added a section to my answer that shows how to plot the third column in your original text file (Data1). To plot the next column over you would use plot(clean_data(:,1),clean_data(:,3)); datetick;

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