Editing CSFUNC, not working without C,D matrices

I am trying to implement a continious function using S function, i tried editing csfunc file in toolbox/simulink/blocks

but the file is not working without C and D matrix . I have only A and B matrices of the system and i need to calculate dx/dt=Ax+Bu

As output i need the state vector x

I am learning to implement Sfunction and will highly appreciate your help,Thank you,Have a nice day

[Kaustubha Govind]

Please explain what you mean by "the file is not working without C and D matrix"? Have you eliminated all uses of 'C' and 'D'? What error/incorrect behavior do you see?

Answer 1

[Omur]

C and D matrices are necessary in a state-space representation, you cannot skip them. But they are easy to find.

As you said, your output is your state vector. So this makes C = identity matrix the size of your state vector and D=0.

Answer 2

[reen2015]

Thank u kastubha and omur. i got it correct.