How to find out the coefficient of a,g,b,c in Continuous Time DSM?

[moorehuang]

How to find out the coefficient of a,g,b,c in Continuous Time DSM?
I knew there are two ways:
* Use realizeNTF_ct function in DStoolbox. But the output of the function is [ABCD,tdac], how to fit them into [a,g,b,c] in certain structure such as CIFB or CIFF?
Also, the option of realizeNTF_ct is 'FF'/'FB', but in DT one, realizeNTF the option is 'CIFB','CIFF''CRFB''CRFF'. Is there any relationship between them?
* Some recommand to derive DT NTF first, and convert it into CT. But when NTF is known, how to find out the coefficient? Is there any function?

Or can anyone kindly to present the Matlab code or simulink model of CT DSM?

Many thanks!

 

[Larsry]

Hi, Im having the same conundrom. Following the dsexample3 Ive done this, not sure yet if it's correct. This procedure gives you the coefficients:

[ABCDc,tdac2]=realizeNTF_ct(ntf, form, tdac);
[Ac Bc Cc Dc] = partitionABCD(ABCDc);

LFc = ss(Ac, Bc, Cc, Dc);

[LF,Gp] = mapCtoD(LFc,tdac);

ABCD = [LF.a LF.b; LF.c LF.d]

[a,g,b,c]=mapABCD(ABCD,typ)

Atleast if you do compare ntf vs ntf_real=calculateTF(ABCD) they are equal

Greatly appreciative of inputs