For full marks, you must include a print$-$out of the $R$ code and relevant plots in your

assignment.

This assignment involves elevation data from a geographic survey of a region in Croatia. The

file croatia.rda contains two datasets: a geodata object $g$ and a standard data frame $d.$ The

output of names $()$ should be clear in both cases.

$($a$)$ Give a brief descriptive and graphical summary of the elevation data in g$.[2$ marks$]$

$($b$)$ By considering a number of trend models, argue that a trend that is linear in the coordinates

is a reasonable choice. You should consider graphical summaries of the residuals, variogram

plots, checks of directionality effects, and permutation tests. Make sure to choose a sensible

maximum distance for the variograms.

marks