Saving signal as a text file

Hi. I am having problems saving a signal as a text file. Let's assume we have the signal below, how can I save xt as a text file with the first column representing the time the second column representing the amplitude?

Fs = 8000; % samples per second
Ts = 1/Fs; % seconds per sample
t = 0: Ts: 3; % Start signals at 0sec and stop after 3sec

% Sine wave x1[n]:
Fc = 1;
x1 = sin(2*pi*Fc*t);

% Sine wave x2[n]:
Fc = 760;
x2 = sin(2*pi*Fc*t);

% Sine wave x3[n]:
Fc = 1280;
x3 = sin(2*pi*Fc*t);

% Sine wave x4[n]:
Fc = 2000;
x4 = sin(2*pi*Fc*t);

xt = x1 + x2 + x3 + x4;

Answer 1

[Image Analyst]

How about making it a csv file:

filename = 'deleteme.csv' % Whatever you want.
csvwrite(filename, [t', xt']);
type(filename) % type to command window.
%delete(filename); % Delete the file.

Answer 2

[Guillaume]

One simple way:

t = table(t', xt', 'VariableNames', {'Time', 'Amplitude'});
writetable(t, 'somefile.txt');

[John Smith]

Thanks for the reply, it worked. Is it possible to save just the data values? I removed {'Time', 'Amplitude'}, but it did not work. Also, how can I replace the commas between the columns with blank spaces?

[Guillaume]

A quick look through the documentation of writetable would have answered both questions:

writetable(t, 'somefile.txt', 'WriteVariableNames', false, 'Delimiter', ' ');

Answer 3

[Image Analyst]

If you want no header and a space between the numbers, use this:

filename = 'deleteme.csv' % Whatever you want.
dlmwrite(filename, [t', xt'], 'delimiter', ' ');
type(filename) % type to command window.

[John Smith]

Thanks it worked. I replaced .csv with .txt to save it as text file.