There are three files in this folder which you can use to test the GIAS programme is working.
1) All Centroids: This is a text file of the UTM (X, Y) coordinates of the centres of volcanic cones in Hawai'i. This shows how to use a text file in GIAS (tick the NN Centroida box) before using 'Load Image'. The NN analysis of these cones suggests they are clustered rather than randomly distributed.


2) Giant's Causeway: Image of columnar basalt jointing. This tests if the the centres of the various shapes are randomly distributed or not. They are not, of course and should have an R value > 1.5 to indicate that the shapes are tending towards regular arrangement.

3) Lak_t_23C_Binary: This is a grey-scale image of a thin section from a basalt taken from the Laki region of Iceland. The vesicles within the thin section show a fabric for example. Read the Computers and Geosciences paper (Beggan and Hamilton, 2010) for a full explanation of the image. An example of the output from the analysis of this image is given in the two text files included in this directory (LAK_t_23cNearestNeighborStats.txt and LAK_t_23cImageAnalysis.txt).


Ciaran Beggan (March 2010)