fft Invalid expression in plot

I'm recieving error "Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters." at the second from last line "plot(t,f,); %amp vs time"

dt = .001;

t = 0:dt:1;

f = data_output;

%%Compute the Fast Fourier Transform FFT

n = length(t);

fhat = fft(f,n); % Compute the fast Fourier transform

PSD = fhat.*conj(fhat)/n; % Power spectrum (power per freq)

freq = 1/(dt*n)*(0:n); % Create x-axis of frequencies in Hz

L = 1:floor(n/2); % Only plot the first half of freqs

%%Use the PSD to filter out noise

indices = PSD>100; % Find all freqs with large power

PSDclean = PSD.*indices; % Zero out all others

fhat = indices.*fhat; % Zero out small Fourier coeffs. in Y

ffilt = ifft(fhat); % Inverse FFT for filtered time signal

%%PLOTS

plot(t,f,); %amp vs time

plot(f,fft); % mag vs freq

Answer 1

[madhan ravi]

 plot(t, f)

Answer 2

[Alia Hicks]

Thanks for your answer Madhan Ravi. I've rewritten it, " plot(t, f), hold on

plot (f, fft);" Now I get the error,

"Error using plot

Vectors must be the same length.

Error in Julytwentyseventh (line 21)

plot(t, f), hold on"