我需要在数据集上实现均值过滤器,但我无法访问信号处理工具箱。有没有办法在不使用for循环的情况下执行此操作?这是我工作的代码:
x=0:.1:10*pi;
noise=0.5*(rand(1,length(x))-0.5);
y=sin(x)+noise; %generate noisy signal
a=10; %specify moving window size
my=zeros(1,length(y)-a);
for n=a/2+1:length(y)-a/2
my(n-a/2)=mean(y(n-a/2:n+a/2)); %calculate mean for each window
end
mx=x(a/2+1:end-a/2); %truncate x array to match
plot(x,y)
hold on
plot(mx,my,'r')
编辑:
在实施merv解决方案后,内置滤波器方法滞后于原始信号。有没有解决的办法?
答案 0 :(得分:5)
使用内置的FILTER功能
%# generate noisy signal
x = sin(0:.1:10*pi);
x = x + 0.5*(rand(1,length(x))-0.5);
%# moving average smoothing
window = 15;
h = ones(window,1)/window;
y = filter(h, 1, x);
%# plot
subplot(211), plot(x), ylim([-1 1]), title('noisy')
subplot(212), plot(y), ylim([-1 1]), title('filtered')
要解决滞后问题,请尝试以下方法:
s = ceil(window/2);
yy = y(s:end);
n = length(x);
plot(1:n, x, 'b'), hold on, plot(1:n-s+1, yy,'r'), hold off
legend({'noisy' 'filtered'})
alt text http://img171.imageshack.us/img171/4510/45062995.png