
80 Applying Analytics: A Practical Introduction
FIGURE 5.2
Voltag e measured by a sensor as a function of time.
5.3.2 Elevation Data
The second example 1-dimensiona l data set I will e xamine is the elevation
as a function of longitude all the way around the Earth’s equator. This is
an evenly spaced circular data set, with about 2 × 10
4
elements. The data
themselves come from the 1 arcminute
4
resolution Earth Topography Digital
Dataset (E TOPO1), published by the U.S. National Geophysical Data Center
(Amante and Eakins 2008). The ETOPO1 is a composite map of the entirety
of the earth’s surface co nstructed from a variety of sources, including satellite ...