Recent content by sodemus

The usual eigenvalues of a LTV system does not say much about the stability but my intuition tells me there should be some kind of extension that applies to LTV systems as well. Like including some kind of inner derivative of the eigenvalues or something, I don't know... I guess in some way...

I ended up using a pretty neat thing I found here: http://www.briancbecker.com/blog/projects/helicopter-visualization/ Brian turns out to be really helpful as well.

I'm simulating helicopter dynamics but would like to better visualize the behavior of the helicopter and so I'm looking for some existing software solution. Ideally this would be similar to an aircraft simulator which would be rather taking position and attitude time series as input instead of...

Thanks for your reply and yes, you got the problem right! Well, that was my first thought as well but I didn't think it actually leads to global maximum/minimum since that assumes knowledge of how the 2 first vectors would contribute to the final sum. Well, perhaps, since the sign of the...

Hi, I have a fairly simple problem which but I'm not sure if it should rather be in a computer science forum for algorithms or something. Given n vectors, how do you choose the sign of each vector as to maximize the modulus of the sum of the vectors? Sure you could go through all 2^n...

Hello everybody! I guess my question is mainly concerned with numerical algorithms... Given a problem of the form min w = f(x) subject to g1(x)=0 : : gn(x)=0 where x is a m x 1 vector, n < m. From a numerical standpoint, how can I know whether it is preferably to solve it by setting up the...

Agreed. :)

I think you were right the first time around. I can't come up with a single case where the signs matter. They change the situation slightly but not in the when it comes to the binary decision making.

Thank you so much Gerenuk! It is exactly what I was looking for! I think solutions exist when the expression lies between 0 and 1. Would that make sense? Anyway, I apologize for my doubt about the circles, I didn't think in the right coordinates. Again, Thanks! Edit: Hah! Quite an interesting...

I don't think it's really an ellipse, and certainly not for all parameter values (I might be wrong though). Look at the where a1+1>C1 for example. Anyway, I agree with you, I think it takes at least two steps of calculations and decisions (pretty simple calculations, but kind of messy in the...

Hey Tim, thanks for the reply! Well, I knew that would be a possibility, I just didn't want to go there since it doesn't really yield a quadratic equation. As far as I can see it does actually give me a intrinsically 4th order equation, doesn't it? And a pretty ugly looking one as well. I was...

So, my question is really simple. What are the requirements for a1, a2, C1, C2 for a real solution to exist for the following system of equations? sin(theta1) + a1*sin(theta2) = C1 cos(theta1) + a2*cos(theta2) = C2 If it would be helpful, I'm not interested in the solution, necessarily (could...

No, obviously not. But what then is the requirement/clause/condition? Assuming the signal is periodic and with a limited bandwidth.

Yes, using the FFT you will not get more information than that. However, the signal is sampled at a rate of 2000 Hz and hence you should in principle be able to reconstruct the entire signal (if it doesn't contain any energy in frequencies higher than or equal to 1000Hz). Having complete...

See my first post. As I also say there, apart from numerical limitations, what is the theoretical catch?