hippocampus: Skeletal representation of hippocampus shapes

In polykde: Polyspherical Kernel Density Estimation

Skeletal representation of hippocampus shapes

Description

Contains skeletal representations (s-reps) for the hippocampus shapes of 177 6-month-old infants. The s-reps models include 168 spokes, and hence the directions of the spokes form a sample on the polysphere (\mathcal{S}^2)^{168}. There are 34 infants that later developed autism.

Usage

hippocampus

Format

A list with six fields:

base

an array of size c(177, 168, 3) with the coordinates of the base points.

bdry

an array of size c(177, 168, 3) with the coordinates of the boundary points.

dirs

an array of size c(177, 168, 3) with the directions of spokes (unit vectors).

rads

a matrix of size c(177, 168) with the radii of the spokes.

ids

hippocampi identifiers.

ids_labs

class labels. TRUE stands for infants that developed autism and FALSE for those that did not.

Source

The fitted s-reps data was shared by Prof. Stephen M. Pizer and Dr. Zhiyuan Liu, see Liu et al. (2021) and the repository https://github.com/ZhiyLiu/shanapy. The source for the raw hippocampi data is the Infant Brain Imaging Study (IBIS) network.

References

Liu, Z., Hong, J., Vicory, J., Damon, J. N. and Pizer, S. M. (2021). Fitting unbranching skeletal structures to objects. Medical Image Analysis, 70:102020. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1016/j.media.2021.102020")}

Examples

# Load data
data("hippocampus")
attach(hippocampus)

# View ith hippocampus s-rep
i <- 50
view_srep(base = base[i, , ], dirs = dirs[i, , ], bdry = bdry[i, , ])

polykde documentation built on June 8, 2025, 1:49 p.m.