How can I skip lines when loading a text file?

Is there a way to use load to load a text file but skip a few lines which contain headers and other info and just load numerical data in columns that come after the headers?

Answer 1

[Sven]

Hi Baba, try importdata:

importdata(FILENAME, DELIM, NHEADERLINES) loads data from ASCII file FILENAME, reading numeric data starting from line NHEADERLINES+1.

[Baba]

for the delimiter, is it possible to set it to any number of spaces, anotherwords, in some rows the distance between my columns is greater than in others because some numbers are longer.

[Sven]

Yes, that's the default behaviour of importdata. Copied from the help:

Using a text editor, create a space-delimited ASCII file with column headers called myfile.txt:

Day1 Day2 Day3 Day4 Day5 Day6 Day7

95.01 76.21 61.54 40.57 5.79 20.28 1.53

23.11 45.65 79.19 93.55 35.29 19.87 74.68

60.68 1.85 92.18 91.69 81.32 60.38 44.51

48.60 82.14 73.82 41.03 0.99 27.22 93.18

89.13 44.47 17.63 89.36 13.89 19.88 46.60

Import the file, specifying the space delimiter and the single column header, and view columns 3 and 5:

M = importdata('myfile.txt', ' ', 1);

for k = [3, 5]

disp(M.colheaders{1, k})

disp(M.data(:, k))

disp(' ')

end

[Sven]

In the MATLAB docs the above data has multiple spaces between some of the data.

[Shania Hurst]

Using importdata with nheaderlines specified works for almost every file for me, but for some reason, I have one file that instead of skipping the first 20 lines as I want, instead imports ONLY the first 20 lines. I have no idea what would cause this to happen, does any one know of any circumstance in which this would happen? The file is a .txt file and has nearly 85k lines of data. The command I used is d = importdata('data.txt',' ',20);

[Walter Roberson]

Shania Hurst, I suggest you consider using readtable() with HeaderLines . (readtable() might even be able to figure out for itself how many header lines are there.)