Why this code gives error?

clear all
close all

N=1001;            
f1=1.0000e9;       
f2=1.0200e9;       
fs=4*f1;           
w1=2*pi*f1/fs;     
w2=2*pi*f2/fs;     


n=0:N-1;
s1=sqrt(1.00)*exp(i*w1*n);
s2=sqrt(0.10)*exp(i*w2*n);
wn=sqrt(0.10)*(randn(1,N)+i*randn(1,N));
x=s1+s2+wn;
x=x(:);


f=0:fs/(N-1):fs;
FFT_abs=abs(fft(x));
plot(f,20*log10(FFT_abs/max(FFT_abs)),'linewidth',3,'b+-');

It gives this error:

Error using plot

Data must be a single matrix Y or a list of pairs X,Y.

Answer 1

[KSSV]

Use:

 plot(f,20*log10(FFT_abs/max(FFT_abs)),'color','b','linewidth',3);

Answer 2

[Stephen23]

Exactly as the plot documentation shows, the LineSpec must come directly after the X/Y data:

plot(f,20*log10(FFT_abs/max(FFT_abs)),'b+-','linewidth',3);

Answer 3

[Walter Roberson]

plot(f,20*log10(FFT_abs/max(FFT_abs)),'b+-','linewidth',3);

Named options must always go after all positional parameters.

Answer 4

[Mathieu NOE]

hello

it works better this way :

plot(f,20*log10(FFT_abs/max(FFT_abs)),'b+-','linewidth',3);

[Sadiq Akbar]

Thank you to all of you. But tell me which answer should I accept now as all have given me the correct asnwer?

[Mathieu NOE]

me, me, !! (I am not yet MVP !!!)

just kidding, pick the one you want . I am not in a beauty conquest

[Mathieu NOE]

what a success . 3 MVP answers for a plot command issue. Wow.

[Sadiq Akbar]

My hear wants to accept all the answers but I think its not possible. Then logically speaking, first of all KSSV has given me the answer, so definitely he has more right though I used the command of Walter Roberson. However thanks to all of you for your prompt responses.

[Walter Roberson]

KSSV's solution does not set the line style or the marker.