contrast {gtexture} | R Documentation |
Contrast Metric for a GLCM
Description
Calculate the contrast feature or metric for a gray-level co-occurrence matrix. For definition and application, see Lofstedt et al. (2019) doi:10.1371/journal.pone.0212110.
Usage
contrast(x, ...)
## Default S3 method:
contrast(x, ...)
## S3 method for class 'matrix'
contrast(x, ...)
## S3 method for class 'FitLandDF'
contrast(x, nlevels, ...)
Arguments
x |
gray-level co-occurrence matrix |
... |
additional parameters |
nlevels |
desired number of discrete gray levels |
Value
double
Examples
## calculate contrast of arbitrary GLCM
# define arbitrary GLCM
x <- matrix(1:16, nrow = 4)
# normalize
n_x <- normalize_glcm(x)
# calculate contrast
contrast(n_x)
# calculate contrast of fitness landscape, assuming 2 discrete gray levels
vals <- runif(64)
vals <- array(vals, dim = rep(4, 3))
my_landscape <- fitscape::FitLandDF(vals)
my_glcm <- get_comatrix(my_landscape, discrete = equal_discrete(2))
contrast(my_landscape, nlevels = 2)
## confirm value of contrast for fitness landscape
# extract normalized GLCM from fitness landscape
contrast(my_glcm) # should match value of above contrast function call
[Package gtexture version 1.0.0 Index]