Home > brede > brede_vol_vol2loc.m

brede_vol_vol2loc

PURPOSE ^

brede_vol_vol2loc - Find location (foci) in a volume

SYNOPSIS ^

function L = brede_vol_vol2loc(S, varargin)

DESCRIPTION ^

 brede_vol_vol2loc    - Find location (foci) in a volume

       function L = brede_vol_vol2loc(V, 'PropertyName',
          'PropertyValue') 
       
       Input:    V         'Vol' structure
           
       Property: NearFilter [ 0.008 ] Filtering of close coordinates  
                 Neighbor   [ 6 | 10 | 18 | {26} ] Selects which 
                            neighborhood rule is used to determine
                            the region 
                 Type       [ CogRegion | {Max} | MaxEq | MaxRegion |
                            MaximaRegion | MaxEqRegion | Min | MinEq |
                            MinRegion | MinimaRegion | MaxEqRegion ] 
                            Location type 
                 VolPValue  { {} | A 'vol' structure ] A 'vol' structure
                            with p-values for setting the 'pValue' field
                            of each location
                 VolPValueCorrected [ {} | A 'vol' structure ] A 'vol'
                            structure with p-values for setting the
                            'pValueCorrected' field of each location
                 VolTValue  [ {} | A 'vol' structure ] A 'vol' structure
                            with t-values for setting the 'tValue' field
                            of each location
                 VolZScore  [ {} | A 'vol' structure ] A 'vol' structure
                            with t-values for setting the 'zScore' field
                            of each location
 
       Output:   L         'Loc' structure array

       This function find the 'hot spots' in a volume. 
 
       The 'max' type will find the local maxima of the voxel which 
       immediate neighboring voxels all have a lower value.
       (The definition of neighbor depending on the 'Neighbor'
       property). 'MaxRegion' will find the maximum in the region,
       performing initial region identification (with
       brede_vol_regident). 'MaximaRegion' can find one or more
       maxima in each region. 'CogRegion' will find the center of
       gravity for the region after region identification.
       'MaxEq' is the same as 'max' with the exception that maxima
       with neighboring voxels with the same value is also included. 

       'Min' type works on the negated volumes compared the 'max'
       type, ie, 'min' type finds the negative peaks.
 
       'NearFilter' will filter maxima that are closer than the value
       given. If it is set to 0.008 then only the first of two maxima
       that are closer than or equal to 8 mm will be returned.

       The following fields of the output location structure array
       are set:
         L.coord    Talairach coordinates in millimeters
         L.value    Value corresponding to the coordinate, eg, the
                    value in S.volume
         L.description  Set from the description field of the volume
                    structure if it is present. 
         L.filename Set from the filename field of the volume
                    structure if it is present.
         L.type     Structure identifier: set to 'loc'

       For 'max' type the entries in the output L is sorted according
       to the value in L.value, so that L(1) contains the location
       with highest L(:).value.

       Example:
         S = brede_read_analyze('spmT_0002');
         L = brede_vol_vol2loc(S);
         % Locations in millimeter and value
         [ cat(1,L.coord)*1000 cat(1,L.value)]

       See also: BREDE, BREDE_VOL, BREDE_LOC, BREDE_READ_ANALYZE,
                 BREDE_VOL_REGIDENT, BREDE_VOL_MAT2VOL,
                 BREDE_VOL_GENCOORD.

 $Id: brede_vol_vol2loc.m,v 1.17 2009/09/25 14:18:01 fn Exp $

CROSS-REFERENCE INFORMATION ^

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