fan.sphere: Creation of spherical fan object.
In espadon: Easy Study of Patient DICOM Data in Oncology

fan.sphere

R Documentation

Creation of spherical fan object.

Description

The fan.sphere function creates a "fan" class object containing, among others, the coordinates of the unit director vectors of the rays of a spherical fan.

Usage

fan.sphere(
  angle = 1,
  method = c("regular", "random"),
  origin = c(0, 0, 0),
  ref.pseudo = "ref1",
  frame.of.reference = "",
  alias = "",
  description = "spherical fan"
)

Arguments

`angle`	Positive number specifying the angle (or mean angle in case of `method = "random"`) between two nearest vectors.
`method`	Requested method of fan calculation from among 'regular' and 'random'. By default, `method = regular`. See details.
`origin`	Numeric vector, giving the xyz coordinates of the fan origin. By default `c (0, 0, 0)`.
`ref.pseudo`	Character string, frame of reference pseudonym of the created object.
`frame.of.reference`	Character string, frame of reference of the created object.
`alias`	Character string, `$alias` of the created object.
`description`	Character string, describing the the created object.

Details

The "regular" and "random" method are explained by Deserno [1].

If method = "regular", the returned vectors composing $xyz matrix are regularly equidistributed at the specified angle.
If method = "random", the returned vectors composing $xyz matrix are randomly equidistributed at the specified angle.

Value

Returns a "fan" class object (see espadon.class for class definitions) containing, among others,

$xyz : a matrix of 3 columns giving the xyz coordinates of the fan rays.
$local : a matrix of 2 columns indicating the polar angle theta (rad) and the azimuthal angle phi (rad) of each ray are added.

References

[1] \insertRefDesernoespadon

Examples

regular.fan <- fan.sphere (angle = 30)
head (regular.fan$xyz)
random.fan <- fan.sphere (angle = 30, method = "random")
head (random.fan$xyz)
if (interactive()){
  rgl::open3d ()
  rgl::points3d (regular.fan$xyz)
  rgl::open3d ()
  rgl::points3d (random.fan$xyz)
}

espadon documentation built on April 11, 2025, 5:57 p.m.