[Insight-developers] Histogram code

[Jisung Kim]

Hi. 
There is a method, IncreaseFrequency(measurement
vector, frequency value) that actually does what you
suggested.

The GetMeasurementVector method returns the center (a
vector) of the bin. GetMeasurement(n, dim) returns the
center of n-th bins along the dim-th dimension (which
is a scalar value).

Thanks,

--- "Miller, James V (Research)" <millerjv@crd.ge.com>
wrote:
> I have a few questions on the Histogram class:
>  
> 1. The code for building the histogram is rather
> involved, here is a snippet
> from the HistogramMatchingImageFilter
>  
>       typename HistogramType::IndexType index;
>       typename HistogramType::InstanceIdentifier id;
>       typename HistogramType::MeasurementVectorType
> measurement;
>   
>       measurement[0] = value;
>       index = histogram->GetIndex( measurement );  
> // Step (a)
>       id = histogram->GetInstanceIdentifier( index
> );    // Step (b)
>       histogram->IncreaseFrequency( id, 1 );        
>      // Step (c)
> 
> I read this as: 
>       (a) What is the index of the bin that my
> measurement falls in?
>       (b) What is the "identifier" for this bin?
>       (c) Increase the frequency of said bin
>  
> I would think I just want do the following
>  
>        histogram->InsertMeasurement( measurement ); 
> // or some API like
> this
>  
> and the histogram code will determine what bin that
> measurement falls in and
> update the frequency. Essentially, once I set up the
> structure of histogram,
> I want to treat it rather abstractly.  While the
> index and identifier API's
> provide great power, there are pretty low level it
> all you want to do is
> build a histogram and pull off quantiles.
>  
>  
> 2. What does the
> GetMeasurement(id)/GetMeasurementVector method do on
> a
> histogram? Does it return the bin center?
> 
>  <?xml:namespace prefix = o ns =
> "urn:schemas-microsoft-com:office:office"
> />
> 
> Jim Miller 
> _____________________________________
> Visualization & Computer Vision
> GE Research
> Bldg. KW, Room C218B
> P.O. Box 8, Schenectady NY 12301
> 
> millerjv@research.ge.com
> <mailto:millerjv@research.ge.com> 
> 
> james.miller@research.ge.com
> (518) 387-4005, Dial Comm: 8*833-4005, 
> Cell: (518) 505-7065, Fax: (518) 387-6981 
> 
>  
> 
>  
> 


=====
Jisung Kim
bahrahm@yahoo.com
106 Mason Farm Rd.
129 Radiology Research Lab., CB# 7515
Univ. of North Carolina at Chapel Hill
Chapel Hill, NC 27599-7515

__________________________________________________
Do you Yahoo!?
Yahoo! Platinum - Watch CBS' NCAA March Madness, live on your desktop!
http://platinum.yahoo.com