Skipping lines in text file

Hello, I have a text file called Acc that has two columns of data. The first has text and i want it to skipped. Can anyone help me solve it. I am a new user.

Here is how I load the data;

load 'Acc.txt';
time = Acc(:,1); 
Acc_x = Acc(:,2);

Thank you

Muhsin

Answer 1

[Guillaume]

Most likely, you could read the file very simply with:

t = readtable('Acc.txt');

which, if the first line is a header, should parse the header correctly and name the columns correctly. if that doesn't work you can always tell readtable to skip the first line:

t = readtable('Acc.txt', 'HeaderLines', 1);

Note that reading a file as a table is much better than popping variables with unpredictable names in your workspace.

[Muhsin]

Hello Guillaume;

can you please help me with attached file? It does not read the file as two columns even though it worked well just one hour ago. After I closed and reopened the software, the code stopped working. Here is my script;

clc;

clear;

t = readtable('Acc.txt');

time = Acc(:,1); %assigns the first column to be time (sec)

Acc_x = Acc(:,2); % assigns the second column to be acceleration (g)

Fs = 1/(time(2)-time(1)); %sampling frequency

L=length(Acc_x); %length of signal

T=1/Fs; %sampling period

Thank you

[Star Strider]

I gave you a way to correctly read your file using the dlmread function in my Answer to your original Question: single sided amplitude fourier spectrum (link).

[Guillaume]

Well, of course your doesn't work. The file is read into a table named t. It does not create a variable acc.

Please read about tables and how to use them. An easy way to do what you want:

acc = readtable('Acc.txt');  %read file into table acc
acc.Properties.VariableNames = {'Time', 'Acc_x'};  %rename columns of the table
FS = 1 / (acc.Time(2) - acc.Time(1));
L = height(acc);
T = 1 / FS;

Use acc.Time to get the time column and acc.Acc_x to get the acceleration column.

[Muhsin]

The code still gives me one column in workspace :(

[Guillaume]

No, the code gives you one table, acc, with two columns. As I said:

"Use acc.Time to get the time column and acc.Acc_x to get the acceleration column."

By the way, there's a lot of empty lines in your text file that matlab interpret as NaNs. To remove this invalid entries

acc = rmmissing(acc);

You can clearly see that acc is a table with two columns (variables):

>> summary(acc)
Variables:
    Time: 1400×1 double
        Values:
            Min        0.01 
            Median    7.005 
            Max          14 
    Acc_x: 1400×1 double
        Values:
            Min         -0.22004
            Median    -0.0058509
            Max          0.20067