a three or four dimensional real array. If two images are
overlaid, then this is the one at bottom.
vol2
a three or four dimensional real array. If two images are
overlaid, then this is the one on top. The default value is
NULL, when only vol1 is drawn.
rlim1
the minimum and maximum vol1 values for which
colors should be plotted, defaulting to the range of the values of
vol1.
rlim2
the minimum and maximum vol2 values for which
colors should be plotted, defaulting to the range of the values of
vol2, if two images are overlaid.
col1
a list of colors for vol1.
col2
a list of colors for vol2.
main
a character vector; main title for the plot.
scale
real value for scaling embedded plot size.
alpha
real value for transparency level, if two images are
overlaid. The default value is 1.
cross
logical; if TRUE, show cross hairs of current
slices.
layout
a character string specifying the layout. It must be
either "counterclockwise" or "clockwise", and may be abbreviated.
The default is "counterclockwise". Images corresponding to
the x-y planes are always displayed in the third quadrant.
If layout is counterclockwise, then the first quadrant
shows images from the y-z planes and the second quadrant the x-z
planes. Otherwise, the images in the first and the second quadrant
are switched. The fourth quadrant is left for the slider used to
select the value of the fourth index (if any) of input array(s).
Details
Shows slices of 3D array along the axes as produced by image,
along with sliders for controlling which slices are shown. For 4D
data an additional slider selects the value of the fourth index.
Two images can be overlaid. This is useful for viewing medical imaging
data (e.g. PET scans and fMRI data).
Examples
#Example 1: View of a mixture of three tri-variate normal densities
nmix3 <- function(x, y, z, m, s) {
0.4 * dnorm(x, m, s) * dnorm(y, m, s) * dnorm(z, m, s) +
0.3 * dnorm(x, -m, s) * dnorm(y, -m, s) * dnorm(z, -m, s) +
0.3 * dnorm(x, m, s) * dnorm(y, -1.5 * m, s) * dnorm(z, m, s)
}
x<-seq(-2, 2, len=40)
g<-expand.grid(x = x, y = x, z = x)
v<-array(nmix3(g$x,g$y,g$z, .5,.5), c(40,40,40))
slices3d(vol1=v, main="View of a mixture of three tri-variate normals", col1=heat.colors(256))
## Not run:
#Example 2: Put a z-map from fMRI data on top of a structure
# image. The threshold value of the z-map is 2.
library(AnalyzeFMRI)
temp<-f.read.analyze.volume("standard.img")
z<-f.read.analyze.volume("z-map.img")
slices3d(vol1=temp, vol2=z[,,,1], rlim2=c(2,Inf),col2=heat.colors(20),
main="Regions above threshold values.")
## End(Not run)