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Contour plot of the t distribution in
bivt.contour(x, type = "alr", n = 100, appear = TRUE)
A matrix with compositional data. It has to be a 3 column matrix.
This is either "alr" or "ilr", corresponding to the additive and the isometric log-ratio transformation respectively.
The number of grid points to consider over which the density is calculated.
Should the available data appear on the ternary plot (TRUE) or not (FALSE)?
A ternary diagram with the points (if appear = TRUE) and the bivariate t contour lines.
The alr or the ilr transformation is applied to the compositional data at first and the location, scatter and degrees of freedom of the bivariate t distribution are computed. Then for a grid of points within the 2-dimensional simplex the bivariate t density is calculated and the contours are plotted along with the points.
Aitchison J. (1986). The statistical analysis of compositional data. Chapman \& Hall.
diri.contour, mixnorm.contour, norm.contour, skewnorm.contour
# NOT RUN {
x <- as.matrix( iris[, 1:3] )
x <- x / rowSums(x)
bivt.contour(x)
bivt.contour(x, type = "ilr")
# }
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