Description Usage Arguments Details Value References See Also Examples
Evaluate the quality of the Growing Region partition regarding several homogeneity parameters.
1 2 3 |
contrast |
the contrast value of each observation. numeric vector. REQUIRED. |
W |
the neighbourhood matrix. dgCMatrix. REQUIRED. |
seed |
the index of the initial seeds or a binary indicator of the initial seeds. positive integer vector or logical vector. REQUIRED. |
sigma |
the sequence of maximum admissible values for the group variability positive numeric vector. REQUIRED. |
criterion.transition |
should the boundary criterion based on the transition levels be computed ? logical. |
criterion.sdfront |
should the boundary criterion based on the standard deviation be computed ? logical. |
criterion.entropy |
should the region criterion based on the entropy be computed ? logical. |
criterion.Kalinsky |
should the region criterion based on the Kalinsky index be computed ? logical. |
criterion.Laboure |
should the region criterion based on the Laboure index be computed ? logical. |
verbose |
should the execution of the function be traced ? logical. |
... |
arguments to be passed to |
ARGUMENTS:
Information about the window
, filename
, width
, height
, path
, unit
and res
arguments can be found in the details section of initWindow
.
Information about the mar
and mgp
arguments can be found in par
.
FUNCTION:
This implementation of the automated Growing Region algorithm was proposed by (Revol et al. 2002) : criterion.transition
corresponds to w2, criterion.sdfront
corresponds to w3 where m=f(x), criterion.entropy
corresponds to S(sigma_max) and criterion.Laboure
corresponds to InvDGL(sigma).
criterion.Kalinsky
corresponds to the Kalinsky criterion which is the ratio of the variance between groups over the variance withing groups.
An list containing :
[[df.criterion]]
: the value of the clustering criterion (in columns) for each sigma value (in rows). numeric matrix.
[[list.GR]]
: the list of the optimal GR sets, one for each clustering criterion.
[[best]]
: the optimal value of each clustering criterion. data.frame.
[[n.max]]
: the number of observations. integer.
Chantal Revol-Muller, Francoise Peyrin, Yannick Carrillon and Christophe Odet. Automated 3D region growing algorithm based on an assessment function. Pattern Recognition Letters, 23:137-150,2002.
plotSigmaGR
for a graphical display of the quality criteria.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 | ## Not run:
## load an \code{MRIaggr} object
data(MRIaggr.Pat1_red, package = "MRIaggr")
calcThresholdMRIaggr(MRIaggr.Pat1_red, param = c("TTP_t0","MTT_t0"), threshold = 1:10,
name_newparam = c("TTP.th_t0","MTT.th_t0"),
update.object = TRUE, overwrite = TRUE)
## display raw parameter
multiplot(MRIaggr.Pat1_red, param="TTP.th_t0", num = 3, numeric2logical = TRUE,
index1 = list(coords = "MASK_DWI_t0", outline = TRUE))
## extract raw parameter, coordinates and compute the neighbourhood matrix
carto <- selectContrast(MRIaggr.Pat1_red, num = 3, hemisphere = "lesion",
param = c("TTP.th_t0","TTP_t0","MASK_DWI_t0"))
coords <- selectCoords(MRIaggr.Pat1_red, num = 3, hemisphere = "lesion")
W <- calcW(coords, range = sqrt(2))$W
## the seed is taken to be the point with the largest TTP in the lesion mask
indexN <- which(carto$MASK_DWI_t0 == 1)
seed <- indexN[which.max(carto[indexN,"TTP_t0"])]
## find optimal sigma
resGR_sigma <- calcSigmaGR(contrast = carto$TTP.th_t0, W = W, seed = seed,
sigma = seq(1,4,0.1), iter_max = 50,
keep.upper = TRUE)
## display quality criteria according to sigma
plotSigmaGR(resGR_sigma)
## display retained region
multiplot(MRIaggr.Pat1_red, param = "TTP.th_t0", num = 3, numeric2logical = TRUE,
index1 = list(coords = coords[resGR_sigma$list.GR$entropy,], outline = TRUE))
multiplot(MRIaggr.Pat1_red, param = "TTP.th_t0", num = 3, numeric2logical = TRUE,
index1 = list(coords = coords[resGR_sigma$list.GR$Kalinsky,], outline = TRUE))
## find optimal sigma
resGR_sigma <- calcSigmaGR(contrast = carto$TTP.th_t0, W = W, seed = seed,
sigma = seq(1,4,0.1), iter_max = 50,
keep.upper = TRUE, keep.lower = TRUE)
## display quality criteria according to sigma
plotSigmaGR(resGR_sigma)
## display retained region
multiplot(MRIaggr.Pat1_red, param = "TTP.th_t0", num = 3, numeric2logical = TRUE,
index1 = list(coords = coords[resGR_sigma$list.GR$entropy,], outline = TRUE))
multiplot(MRIaggr.Pat1_red, param = "TTP.th_t0", num = 3, numeric2logical = TRUE,
index1 = list(coords = coords[resGR_sigma$list.GR$Kalinsky,], outline = TRUE))
## End(Not run)
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