gdi - Volumetric Analysis using Graphic Double Integration
Tools implementing an automated version of the graphic
double integration technique (GDI) for volume implementation,
and some other related utilities for paleontological
image-analysis. GDI was first employed by Jerison (1973)
<ISBN:9780323141086> and Hurlburt (1999)
<doi:10.1080/02724634.1999.10011145> and is primarily used for
volume or mass estimation of (extinct) animals. The package
'gdi' aims to make this technique as convenient and versatile
as possible. The core functions of 'gdi' provide utilities for
automatically measuring diameters from digital silhouettes
provided as image files and calculating volume via graphic
double integration with simple elliptical, superelliptical
(following Motani 2001
<doi:10.1666/0094-8373(2001)027%3C0735:EBMFST%3E2.0.CO;2>) or
complex cross-sectional geometries (see also Zhao 2024
<doi:10.7717/peerj.17479>). Additionally, the package provides
functions for estimating the center of mass position (COM), the
moment of inertia (I) for 3D shapes and the second moment of
area (Ix, Iy, Iz) of 2D cross-sections, as well as for the
visualization of results.
