


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 $