我正在尝试在我的数据上生成低通模拟butterworth过滤器
数据文件
https://www.dropbox.com/sh/m5wx8h4vj4bv0pf/AACLJeOIIgcjwfjYgnItmau-a?dl=0
x = importdata('data.txt') %data in timedomain [voltage]
t = importdata('time.txt') %time [s]
fs = sampling frequency
w_c = 2*pi*1700; %cut off freq. 1700 Hz
n = 1; %1st order filter
[zb,pb,kb] = butter(n,2*pi*w_c,'low','s'); % analog butterworth filter with zeros og poles output
[bb,ab] = zp2tf(zb,pb,kb); % z&p to a transferfunc.
[hb,wb] = freqs(bb,ab,1e3); %making shure that the damping is correct
[b,a] = bilinear(bb,ab,fs); % analog to digital filter
x_filter = filter(b,a,x); % apply filter on the data
我不确定过滤时域数据的方法是否正确？使用对数时间缩放对数据建模，以获得电压衰减的早期和晚期变化。我该如何确定采样频率？