Re: [Bayes++] Usage question

[Michael S. <Mic...@ep...>]

Rob Ottenhoff wrote:
> Hello,
>  
> First of all I thank mr.stevens for this fine library. Now my question:
> I try to transform the PV-sample into a 'tracker' that tracks 2D points.
> If I implement the tracker using two 1D-filters like in the sample it 
> works fine. But if I use only one 2D-filter my tracker works fine for 
> the x-coordinate, but not at all for the y-coordinate ( the velocity in 
> the y-direction quickly becomes almost zero). I fail to see what I do 
> wrong here. Here follows the code I used:
>  

Hello Rob,

I have had a quick look at your problem. Firstly you are correct in
suspecting a coding error. In this special case the solution with one 2D
filters should give identical results as the case with two 1D filters.

Looking at your code the mistake seems to be in your noise coupling
matrix G.
After the identity(G) it will have the value
1 0
0 1
0 0
0 0

I think what you want is
1 0
0 0
0 1
0 0

That way the noise is correctly added to the X position and Y position
states. I think that is all that is wrong. Can you tell me if that
doesn't work.


Of course the problem could be you have backslashes instead of forward
slashes in your #included filenames!! :-)
Slightly more seriously, the 'b' in Bayes++ is always capitalised in my
distributions. So unless you have a case agnostic OS your code will no
be portable.

All the best,
	Michael

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