Read text file efficiently

Hi all,

Does anybody has an idea how to efficiently read a *.txt-file in following format:

1/ 2/2019 01:30 -1.59 0.39 253

1/ 2/2019 01:45 -1.78 0.35 250

1/ 2/2019 02:00 -1.94 0.31 246

1/ 2/2019 02:15 -2.07 0.26 240

I would like to have 8 columns (day, month, year,hour, minute, param1, param2, param3).

The file also has some headers btw.

Like to hear your advise!

[Stephen23]

https://www.mathworks.com/help/matlab/ref/readtable.html

[Image Analyst]

Don't forget to attach your text file again, if you still need help.

There are lots of input options, like importdata(), textscan(), etc. if readtable() doesn't work.

Answer 1

[Walter Roberson]

fid = fopen('YourFile.txt', 'rt');
data = cell2mat( textscan(fid, '%f/%f/%f %f:%f %f %f %f', 'collectoutput', true);
fclose(fid);

[Walter Roberson]

filename = 'test.txt';
fid = fopen(filename, 'rt');
location_cell = textscan(fid, 'Location: %f° %f'' %f" %c %f° %f'' %f" %c%*[^\n]', 1, 'Headerlines', 1);
data = cell2mat( textscan(fid, '%f/%f/%f %f:%f %f %f %f', 'collectoutput', true, 'Headerlines', 6) );
fclose(fid);
lat = location_cell{1} + location_cell{2}/60 + location_cell{3}/3600;
if strcmpi(location_cell{4}, 's'); lat = -lat; end
long = location_cell{5} + location_cell{6}/60 + location_cell{7}/3600;
if strcmpi(location_cell{8}, 'w'); long = -long; end

%outputs: lat, long, data

[Mjan88]

Thanks, Walter Roberson. This works fine, except that for some kind of reason the first two data-lines are skipped. I don't know what causes this. Do you have an idea?

[Walter Roberson]

You could try reducing HeaderLines to 4 on the second textscan. But I tested on your supplied file and the output looked fine to me.

Answer 2

[Mjan88]

Thanks for the suggestions. Textscan seems to work better indeed, IF I do not have headers. Like Image Analyst already suggested, hereby the textfile itself. Does anybody have an idea how to obtain longitude, latitude, and the data itself (day, month, year,hour, minute, param1, param2, param3)? Thanks!