| Abstrakt: |
ANGLE interprets measurements of either directional (modulo 360 degrees ) or axial (modulo 180 degrees ) orientation data on the circle, such as vertical dike azimuths, tectonic lineaments, glacial striae, crossbed directions, crystal or fossil orientations on foliation surfaces, etc. The user is allowed extensive selection of input-data formats, notations, etc. Single samples (sets of measurements) can be tested for a null hypothesis of uniformity (i.e., lack of preferred orientation), using the nonparametric Hodges-Ajne, Kuiper, and Watson U sup 2 tests and the parametric Rayleigh tests, against the following alternative hypotheses: (1) a single, unspecified preferred orientation; (2) a single, prespecified mean orientation; or (3) for directional data only, a preferred axial orientation (i.e., a bimodal distribution with two diagonal modes). Estimated mean directions and concentration parameters also are calculated for each input file, assuming a Von Mises distribution. For two or more samples, the nonparametric Mardia (uniform scores) and Watson U sup 2 tests, and the parametric Watson-Williams test can be used additionally to indicate whether the samples may come from populations with (1) equal mean directions, or (2) mean directions differing by a predetermined amount. [ABSTRACT FROM AUTHOR] |
