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seen Dec 9 '13 at 11:18

Jul
2
awarded  Curious
Jul
31
comment Using WhenEvent for derivative of discontinuous function
@Nasser Good point! I've replaced UnitBox with HeavisidePi, but it still doesn't work.
Jul
31
comment Using WhenEvent for derivative of discontinuous function
@Nasser Isn't the derivative of a square wave a series of dirac delta functions, each positioned where the amplitude changes?
Jul
30
revised Using WhenEvent for derivative of discontinuous function
Changed code to remove error message, which is clearer after updating to 9.0.1
Jul
30
comment Using WhenEvent for derivative of discontinuous function
I was using 9.0.0 on OS X, but updated to 9.0.1 and now I also see the proper error message. I'll update the question.
Jul
29
asked Using WhenEvent for derivative of discontinuous function
Jun
27
comment Adding noise to nonlinear control system using NDSolve
Sorry, you're right. I increased the $\sigma$ of the distribution and I can see the changes.
Jun
27
comment Adding noise to nonlinear control system using NDSolve
No, when I plot x[t] and e[t] the segments between events/state changes are straight lines. This shows up clearer when you plot from 0-30 instead of 0-60. Is it possible that it should be v[t] instead of just v?
Jun
27
comment Adding noise to nonlinear control system using NDSolve
Great, that seems to work well. However, I had to increase MaxSteps -> 30000 to be able to plot it?
Jun
27
comment Adding noise to nonlinear control system using NDSolve
It seems that the noise value is constant for different values of t, or at least when I try to plot it?
Jun
27
accepted Adding noise to nonlinear control system using NDSolve
Jun
27
asked Adding noise to nonlinear control system using NDSolve
Apr
12
awarded  Commentator
Apr
12
comment Using transfer function model to generate state space model
I expected there would be equivalent state-space representations, but wanted to know how I can use Mathematica to produce the same matrices as in the reference. Your other answer does this beautifully, thank you.
Apr
12
accepted Using transfer function model to generate state space model
Apr
11
comment Using transfer function model to generate state space model
While I believe that you're right, can you please explain how you got to that conclusion? For reference, I'm working from pg. 177 of this report (on my dropbox). The original link is down for maintenance.
Apr
11
comment Using transfer function model to generate state space model
You're correct: there is a term $w_1(t)$. I've edited the question to reflect this.
Apr
11
revised Using transfer function model to generate state space model
Added noise term w1(t)
Apr
11
comment Using transfer function model to generate state space model
@SubaThomas, I'm not sure I understand what you mean. How is $x_1(t) = e^{-2t}$ ? By the way, while it didn't solve my problem above, your first comment was quite helpful in fixing some of my other "transfer function to state space" conversions.
Apr
8
comment Using transfer function model to generate state space model
$y_2(t) = \dot{x}_2(t) = x_1(t) + u(t)$, which is why I'm expecting the first C matrix. As shown in the figure, $u(t)$ and the white noise are added to get a single input to the system. If you would like more context on the Human block, refer to this related question.