[Insight-users] Re: question about demons

[Kent Williams]

You can evaluate the time complexity of an algorithm, but this has two 
disadvantages in this context:

1) Time complexity is T(n), for an input of size n, and formally is the 
asymptotic upper bound on the time to complete the algorithm. In other 
words, 'worst case' scenario.  In the case of registration algorithms, 
you're more interested in 'average case.' You're starting with organized 
images that are nominally similar -- you don't try and register a fibia 
with a cranium.

2. Thirion Demons is complicated enough that to formally evaluate its 
time complexity would take quite a while, and give you a proper computer 
scientists' headache!

So your suggestion is apt -- try some tests and see what happens. But 
there is such a thing as scientifically valid generalization -- and 
often rigorously provable generalizations are quite valuable.

Luis Ibanez wrote:

>
> Any *generalization claims* are the evidence of *bad science*,
> and *superficial thinking*. That's fine if your purpose in life
> is to publish papers in vanity journals with the goal of
> fulfilling your annual quota of "intellectual productivity",
> but if you want to do honest technical work, then you must
> stick to the scientific method, run experiments, and limit
> your conclusions to the cases covered by the experiments.
>
> ---------------------------------
> Alma Rosas Rugerio Ramos wrote:
>
>> Hello!
>>
>> I would like to know about the computational cost of the demons 
>> deformable  registration and affine registration but in the paper of 
>> the Thirion doesn´t mention it, can you help me please?
>> thanks
>>
>>
>
> _______________________________________________
> Insight-users mailing list
> Insight-users at itk.org
> http://www.itk.org/mailman/listinfo/insight-users
>