legend problem Not enough input arguments

The legend of the picture is chaos.

[Walter Roberson]

Please show your code.

[Tian Lan]

clear all
close all
clc
fs=10e3;
f0=3e3;
w0=2*pi*f0;
c=1500;
lambda=c/f0;
array_num=10;
% array_d=0.5*lambda;
array_d=lambda/2;
array_layout=[0:array_num-1].'*array_d; 
snapnum=500;
unitrad=pi/180;
theta_target=[0]*unitrad; 
SNR=[20];
TargetNum=length(theta_target);  
a_target=exp(1i*2*pi*array_layout*sin(theta_target)/lambda); 
tic
X=(ones(array_num,1)*10.^(SNR/20)).*a_target*randn(TargetNum,snapnum);  X=A*s（10*500）
Noise=randn(array_num,snapnum);  
X_rec=X+Noise;   
Rx=X_rec*X_rec'/snapnum;   
% Rx=a_target*diag(10.^(SNR/10))*a_target'+eye(array_num);
index_P=0;
for theta=-90:0.5:90
    theta_rad = theta*pi/180;
    index_P=index_P+1;
    tao=array_layout*sin(theta_rad)/c;  
    w=exp(1i*w0*tao);  
    w=w/(w'*w);     
    P(index_P)=abs(w'*Rx*w); 
end
plot(-90:0.5:90,10*log10(P/max(P)));
toc
index_P=0;
for theta=-90:0.5:90
    theta_rad = theta*pi/180;
    index_P=index_P+1;
    tao=array_layout*sin(theta_rad)/c;   
    a=exp(1i*w0*tao);    
    w_mvdr=inv(Rx)*a/(a'*inv(Rx)*a);
    unitrad(index_P,1)=(a'*inv(Rx)*a);
    P_MVDR(index_P)=abs(w_mvdr'*Rx*w_mvdr);
end
hold on
plot(-90:0.5:90,10*log10(P_MVDR/max(P_MVDR)))
[vec,val]=eig(Rx);  
[eigval,eigindx]=sort(diag(val),'descend');   
Un=vec(:,eigindx(TargetNum+1:end));
index_P=0;
for theta=-90:0.2:90
    theta_rad = theta*pi/180;
    index_P=index_P+1;
    tao=array_layout*sin(theta_rad)/c;
    a=exp(j*w0*tao);
    P_MUSIC(index_P)=(a'*a)/abs(a'*Un*Un'*a);  
    norm(a'*Un); 
end
plot(-90:0.2:90,10*log10(P_MUSIC/max(P_MUSIC)));
legend('CBF','MVDR','MUSIC')%,'orientation','horizontal'
title('空间谱')
xlabel('角度/°')
ylabel('归一化空间谱')

[Walter Roberson]

Caution: your line

X=(ones(array_num,1)*10.^(SNR/20)).*a_target*randn(TargetNum,snapnum);  X=A*s（10*500）

includes U+FF08 and U+FF09, which are "full width left parenthesis" and "full width right parenthesis" . It is the

X=A*s（10*500）

The two characters that show up in red here are not ( and ), they are "full width" parenthesis.

If you change that to

X=A*S(10*500)

then you have the problem that S only has 16 elements. Perhaps it is

X=A*S*(10*500)

??