>> % 定义信号参数
A1 = 1;
A2 = 1;
A3 = 1;
f1 = 2;
f2 = 4;
f3 = 8;
t = 0:0.01:15;
% 定义非平稳信号和平稳信号
x1 = A1*sin(2*pi*f1*t).*(t>=0 & t<5) + A2*sin(2*pi*f2*t).*(t>=5 & t<10) + A3*sin(2*pi*f3*t).*(t>=10 & t<=15);
x2 = A1*sin(2*pi*f1*t) + A2*sin(2*pi*f2*t) + A3*sin(2*pi*f3*t);
% 加入不同严重程度的白噪声
noise_levels = [0, 0.5, 1]; % 不同严重程度的白噪声
x1_noisy = zeros(length(noise_levels), length(x1));
x2_noisy = zeros(length(noise_levels), length(x2));
for i = 1:length(noise_levels)
noise = noise_levels(i)*randn(size(x1));
x1_noisy(i, :) = x1 + noise;
x2_noisy(i, :) = x2 + noise;
end
% 小波分析
figure;
for i = 1:length(noise_levels)
subplot(length(noise_levels), 2, (i-1)*2+1);
[wt, f] = cwt(x1_noisy(i, :), 'amor', 1/0.01, 'VoicesPerOctave', 12, 'FrequencyLimits', [0 10]);
imagesc(t, f, abs(wt));
set(gca, 'YDir', 'normal');
title(['CWT of Noisy Non-Stationary Signal (Noise Level ', num2str(noise_levels(i)), ')']);
xlabel('Time (s)');
ylabel('Frequency (Hz)');
subplot(length(noise_levels), 2, i*2);
[wt, f] = cwt(x2_noisy(i, :), 'amor', 1/0.01, 'VoicesPerOctave', 12, 'FrequencyLimits', [0 10]);
imagesc(t, f, abs(wt));
set(gca, 'YDir', 'normal');
title(['CWT of Noisy Stationary Signal (Noise Level ', num2str(noise_levels(i)), ')']);
xlabel('Time (s)');
ylabel('Frequency (Hz)');
end
我按照题目所给的频率设定,为什么结果成像却出错,结果成像不在2,4,8上