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Re: x-y offsets [message #70948]

Thu, 20 May 2010 13:11

Jeremy Bailin
Messages: 618
Registered: April 2008

Senior Member

> I think once you have a set of plausible distance pairs, it becomes
> a minimization problem. How about if, once you have a set of
> possible pairs from the "distogram" reverse_indices, you construct
> a function that calculates the total distance squared between
> all of the pairs and use something like POWELL to minimize it?

To be more specific, I would go with calculating the mean offset
using the reverse_indices to get you close, then use
MATCHALL_2D using the offset coordinates to get neighbours of
each x1,y1 pair. Then you can minimize the following function
for xoff,yoff:

Sum_i ( min( (x1_i-x2+xoff)^2 + (y1_i-y2+yoff)^2 ) )

where i runs over x1,y1 and the minimization is over all x2,y2
points that are neighbours of x1_i,y1_i.

-Jeremy.

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[Message index]

		Re: x-y offsets By: Jeremy Bailin on Thu, 20 May 2010 13:11
		Re: x-y offsets By: Jeremy Bailin on Thu, 20 May 2010 12:20
		Re: x-y offsets By: Gray on Thu, 20 May 2010 08:01
		Re: x-y offsets By: Jeremy Bailin on Wed, 19 May 2010 21:59
		Re: x-y offsets By: Jeremy Bailin on Wed, 19 May 2010 19:56
		Re: x-y offsets By: Craig Markwardt on Wed, 19 May 2010 18:45
		Re: x-y offsets By: Jeremy Bailin on Wed, 19 May 2010 18:38
		Re: x-y offsets By: Gray on Wed, 19 May 2010 12:45
		Re: x-y offsets By: Jeremy Bailin on Tue, 18 May 2010 23:50
		Re: x-y offsets By: Gray on Tue, 18 May 2010 14:08

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