spMC (version 0.3.15)

persp.pemt: Perspective Plots with Multi-directional Transiograms

Description

The function draws perspective-plots the \(2\)-D sections of a multi-directional transiogram computed without any ellipsoidal interpolation.

Usage

# S3 method for pemt
persp(x, main, mar, ask = TRUE, col = "white", ...)

Value

An image is produced on the current graphics device. No values are returned.

Arguments

x

an object of the class pemt, typically with the output of the function pemt.

main

the main title (on top) whose font and size are fixed.

mar

a scalar or a numerical vector of the form c(bottom, left, top, right) which gives the number of margin lines to be specified on the four sides of image to plot. See par(mar=.).

ask

a logical value; if TRUE, the user is asked for input, before each plot. See par(ask=.).

col

a list of colors which is usually generated by rev(heat.colors()), or with other function for colors.

...

other arguments to pass to the function persp.

Author

Luca Sartore

Details

A multidimensional transiogram is a diagram which shows the transition probabilities for a single pair of categories. The probability is computed for any lag vector \(h\) through $$\mbox{expm} (\Vert h \Vert R_h),$$ where entries of \(R_h\) are not ellipsoidally interpolated, but they are estimated for the direction specified by the vector \(h\).

The exponential matrix is evaluated by the scaling and squaring algorithm.

References

Carle, S. F., Fogg, G. E. (1997) Modelling Spatial Variability with One and Multidimensional Continuous-Lag Markov Chains. Mathematical Geology, 29(7), 891-918.

Higham, N. J. (2008) Functions of Matrices: Theory and Computation. Society for Industrial and Applied Mathematics.

Sartore, L. (2010) Geostatistical models for 3-D data. M.Phil. thesis, Ca' Foscari University of Venice.

See Also

pemt, persp.multi_tpfit, persp, multi_tpfit, image.pemt, plot.transiogram

Examples

# \donttest{
data(ACM)

# Compute a 2-D section of a
# multi-directional transiogram
psEmpTr <- pemt(ACM$MAT3, ACM[, 1:3], 2,
                max.dist = c(200, 200, 20), 
                which.dire = c(1, 3))

# 3D-Plot for a 2-D sections of
# a multi-directional transiogram
persp(psEmpTr, col = rainbow(500), mar = .7,
      theta = 15, phi = 45)
# }