What does x(1,:) do in MATLAB ?

eg:

at = sqrt(Po)*exp(-0.5*(1+i*C)*(tau./t0).^(2*m))
a0 = fft(at(1,:));

what does at(1,:) do here ?What does x(1,:) do in MATLAB ?

eg:

at = sqrt(Po)*exp(-0.5*(1+i*C)*(tau./t0).^(2*m))
a0 = fft(at(1,:));

what does at(1,:) do here ? What does x(1,:) do in MATLAB ?

eg:

at = sqrt(Po)*exp(-0.5*(1+i*C)*(tau./t0).^(2*m))
a0 = fft(at(1,:));

what does at(1,:) do here ? syntax MATLAB Answers — New Questions

​