continuous to discrete and plotting

[EDIT: 20110527 15:15 CDT - reformat - WDR]

hey and thanks in advance.

i have a continuous system(A,B,C,D matrices) and what i'm trying to do is:

1. plot on one graph the continuous and equivalent discrete systems response to a sequence of steps moved in time

2. the same only for a run entry

thanks again,

hagai

[Walter Roberson]

Sorry, I do not understand what you mean by a "run entry" ?

[hagai bar]

i'm trying to get the system response to

u1= 1 0<=t<1

2 1<=t<2

3 2<=t<3

0 t>3

and

u2= t 0<=t<=3

0 t>3

trying to get the contiuous and discrete response to u1 and u2

[Walter Roberson]

You only mentioned A, B, C, D matrices before, so I'm not sure how u1 and u2 and t fit in to this?

Is this a transfer system? A control system? A differential equation? Something else?

Answer 1

[hagai bar]

thanks, ended up using c2d

Answer 2

[Walter Roberson]

You might want to use a stairs() plot.

Answer 3

[Paulo Silva]

clf 
hold on
%continous response
%TStart is the starting time of the step
%TIncrement is the increment of the time vector
%TEnd is the end time of your step (when input returns to zero)
sys = ss(A,B,C,D);
step(sys,TStart:TIncrement:TEnd) %choose a small TIncrement
%discrete response
sys = ss(A,B,C,D,Ts); %Ts is your sampling time
step(sys,TStart:Ts:TEnd)