Failure while using function pem of system identification - plot compare shows step at the beginning of the signal trend
1 次查看(过去 30 天)
显示 更早的评论
Hey,
I’m using the function pem to identify a process. When I plot the result with function compare the plot shows a step at the beginning. Does anybody know why this happens?
I used the code:
Ts=1;
z_mittel = iddata(y,u,Ts);
ze_mittel=z_mittel(1:1040);
zv_mittel=z_mittel(1040:2201);
P1DI_mittel=pem(ze_mittel,'P1I');
compare(z_mittel,P1DI);
And the plot result is:
Why do I get the step at the beginnig of the plot? I think as a result of this step the toolbox doesn't provide the best parameters.
Thanks for your help!
0 个评论
采纳的回答
Rajiv Singh
2012-12-21
Difficult to say without looking at the data, but try using zero initial conditions for the comparison:
compare(z_mittel,P1DI, 'init', 'zero');
You may observe that the overall fit is even worse. But then that is just saying that you do not have a good model.
更多回答(0 个)
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Linear Model Identification 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!