Geoscience Reference
In-Depth Information
3 on univariate statistics, the next sections are then on the use of empirical
and theoretical distributions to describe directional data (Sections 10.3 and
10.4). h e last three sections then describe the three most important tests
for directional data, these being the tests for randomness of directional data
(Section 10.5), for the signii cance of a mean direction (Section 10.6), and for
the dif erence between two sets of directional data (Section 10.7).
10.2 Graphical Representation
h e classic way to display directional data is the rose diagram. A rose
diagram is a histogram for measurements of angles. In contrast to a bar
histogram with the height of the bars proportional to frequency, the rose
diagram comprises segments of a circle, with the radius of each sector being
proportional to the frequency. We use synthetic data to illustrate two types
of rose diagram that are used to display directional data. We load a set of
directional data from the i le
directional_1.txt
.
clear
data_degrees_1 = load('directional_1.txt');
Fig. 10.2
Rose diagram to display directional data using the function
rose
. h e radii of
the area segments are proportional to the frequencies for each class. We using
rose
with
view(90,-90)
, so that 0° points due north and 90° points due east, i.e., the angles increase in
a clockwise direction.
