A spherical-plot solution to linking acceleration metrics with animal performance, state, behaviour and lifestyle.
BACKGROUND
We are increasingly using recording devices with multiple sensors operating at high frequencies to produce large volumes of data which are problematic to interpret. A particularly challenging example comes from studies on animals and humans where researchers use animal-attached accelerometers on moving subjects to attempt to quantify behaviour, energy expenditure and condition.


RESULTS
The approach taken effectively concatinated three complex lines of acceleration into one visualization that highlighted patterns that were otherwise not obvious. The summation of data points within sphere facets and presentation into histograms on the sphere surface effectively dealt with data occlusion. Further frequency binning of data within facets and representation of these bins as discs on spines radiating from the sphere allowed patterns in dynamic body accelerations (DBA) associated with different postures to become obvious.


METHODS
We examine the extent to which novel, gravity-based spherical plots can produce revealing visualizations to incorporate the complexity of such multidimensional acceleration data using a suite of different acceleration-derived metrics with a view to highlighting patterns that are not obvious using current approaches. The basis for the visualisation involved three-dimensional plots of the smoothed acceleration values, which then occupied points on the surface of a sphere. This sphere was divided into facets and point density within each facet expressed as a histogram. Within each facet-dependent histogram, data were also grouped into frequency bins of any desirable parameters, most particularly dynamic body acceleration (DBA), which were then presented as discs on a central spine radiating from the facet. Greater radial distances from the sphere surface indicated greater DBA values while greater disc diameter indicated larger numbers of data points with that particular value.


CONCLUSIONS
We indicate how this approach links behaviour and proxies for energetics and can inform our identification and understanding of movement-related processes, highlighting subtle differences in movement and its associated energetics. This approach has ramifications that should expand to areas as disparate as disease identification, lifestyle, sports practice and wild animal ecology. UCT Science Faculty Animal Ethics 2014/V10/PR (valid until 2017).
Swansea Lab for Animal Movement, Biosciences, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP UK.
Rory P
RP
Wilson
Visual Computing, Computer Science, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP UK.
Mark D
MD
Holton
Visual Computing, Computer Science, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP UK.
James S
JS
Walker
Swansea Lab for Animal Movement, Biosciences, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP UK.
Emily L C
EL
Shepard
School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Medical Biology Centre, 97, Lisburn Road, Belfast, BT9 7BL UK.
D Mike
DM
Scantlebury
Swansea Lab for Animal Movement, Biosciences, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP UK.
Vianney L
VL
Wilson
Swansea Lab for Animal Movement, Biosciences, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP UK.
Gwendoline I
GI
Wilson
Swansea Lab for Animal Movement, Biosciences, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP UK.
Brenda
B
Tysse
Institute of Life Science, Swansea University Medical School, Swansea, SA2 8PP UK.
Mike
M
Gravenor
Centro Nacional Patagonico, Boulevard Brown s/n, Chubut, Argentina.
Javier
J
Ciancio
Applied Sports Science Technology and Medicine Research Centre, College of Engineering, Swansea University, Fabian Way, Swansea, SA1 8EN UK.
Melitta A
MA
McNarry
Applied Sports Science Technology and Medicine Research Centre, College of Engineering, Swansea University, Fabian Way, Swansea, SA1 8EN UK.
Kelly A
KA
Mackintosh
Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, Doha, 2713 Qatar.
Lama
L
Qasem
Faculty of Arts and Sciences, Department of Environmental and Health Studies, Telemark University College, N-3800 Bø i, Telemark, Norway.
Frank
F
Rosell
Faculty of Arts and Sciences, Department of Environmental and Health Studies, Telemark University College, N-3800 Bø i, Telemark, Norway ; Department of Integrative Biology and Biodiversity Research, Institute of Wildlife Biology and Game Management, University of Natural Resources and Life Sciences, Vienna, A-1180 Vienna Austria.
Patricia M
PM
Graf
Centro Nacional Patagonico, Boulevard Brown s/n, Chubut, Argentina.
Flavio
F
Quintana
Centro Nacional Patagonico, Boulevard Brown s/n, Chubut, Argentina.
Agustina
A
Gomez-Laich
Centro Nacional Patagonico, Boulevard Brown s/n, Chubut, Argentina.
Juan-Emilio
JE
Sala
School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Medical Biology Centre, 97, Lisburn Road, Belfast, BT9 7BL UK.
Christina C
CC
Mulvenna
School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Medical Biology Centre, 97, Lisburn Road, Belfast, BT9 7BL UK.
Nicola J
NJ
Marks
Visual Computing, Computer Science, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP UK.
Mark W
MW
Jones
G-sphere; Spherical plots; Tri-axial acceleration; Visualisation
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