affiner 0.1.1

Initial features

• affineGrob() and grid.affine() provide wrappers around grid::defineGrob() and grid::useGrob()

  • isocubeGrob() and grid.isocube() provides a convenience wrapper for the isometric cube case.

• affine_settings() computes grid affine transformation feature viewports and transformation functions

  • Available as a “standalone” file that can be copied over into other R packages under the permissive Unlicense.

• angle() creates angle vector S3 classes that allow users to use whichever angular unit is most convenient for them:

  • Supports “degrees”, “radians”, “half-turns” (aka “pi-radians”), (full) “turns”, and “gradians” units.

  • is_angle() tests whether the input is an angle vector.

  • as_angle() casts objects to angle vectors.

  • degrees(), gradians(), pi_radians(), radians(), and turns() are convenience wrappers around as_angle() for those commonly used angular units.

  • is_congruent() is a generic S3 method which tests whether two R objects are “congruent”. The is_congruent() method for angle vectors tests whether two angles are congruent.

  • angular_unit() can be used to get/set the angular unit of angle vectors.

  • The default angular unit can be adjusted locally/globally by setting the “affiner_angular_unit” option. e.g. options(affiner_angular_unit = "turns").

  • sine(), cosine(), tangent(), secant(), cosecant(), cotangent(), arcsine(), arccosine(), arctangent(), arcsecant(), arccosecant(), and arccotangent() are angle vector aware trigonometric functions.

  • We implement methods for several base generics (plus as a numeric vector it inherits support for several more). Some notes:

    • If both objects in a mathematical operation (in particular + and -) or a c() combining operation are angle vectors then we coerce the second one to use the same angular unit as the first one.
    • as.numeric() takes a unit argument which can be used to convert angles into other angular units e.g. angle(x, "degrees") |> as.numeric("radians") to cast a numeric vector x from degrees to radians.
    • abs() will calculate the angle modulo full turns.

• Coord1D, Coord2D, and Coord3D are (Cartesian) coordinate R6 classes

  • is_coord1d(), is_coord2d(), and is_coord3d() test whether objects are Coord1D, Coord2D, or Coord3D R6 classes

  • as_coord1d(), as_coord2d(), and as_coord3d() cast objects to Coord1D, Coord2D, or Coord3D R6 classes

  • Several mathematical operations are supported for Coord1D, Coord2D, or Coord3D R6 classes

    • * either applies a “dot” product (if multiplying another Coord1D, Coord2D, or Coord3D object) or a “scaling” transformation (if multiplying a numeric value)
    • / applies a “scaling” transformation
    • Unary - applies a “scaling” transformation whereas binary - and + apply a “translation” transformation

  • Additional S3 methods:

    • abs() computes Euclidean norm
    • convex_hull2d() computes convex hull (currently just for Coord2D vectors)
    • cross_product3d() computes a cross product between Coord3D vectors
    • distance1d(), distance2d(), and distance3d() computes Euclidean distances
    • mean() computes centroids of coordinates
    • normal2d() computes Coord2D normals
    • normal3d() computes Coord3D normals
    • plot() and points() plots Coord1D and Coord2D coordinates using base graphics. If the suggested {ggplot2} package is installed one may also use autolayer() to plot Coord1D and Coord2D points. If the suggested {rgl} package is installed one may also use plot3d() to plot Coord3D points (or straightforwardly use the primitive points3d()).
    • range() computes axis-aligned ranges

• Point1D, Line2D, and Plane3D R6 classes

  • as_point1d() casts objects to Point1D R6 classes
  • as_line2d() casts objects to Line2D R6 classes
  • as_plane3d() casts objects to Plane3D R6 classes
  • is_point1d() tests whether objects are Point1D R6 classes
  • is_line2d() tests whether objects are Line2D R6 classes
  • is_plane3d() tests whether objects are Plane3D R6 classes

• transform1d(), transform2d(), and transform3d() create 1D/2D/3D affine transformation matrix S3 classes

  • is_transform1d(),is_transform2d(), and is_transform3d() test iftransform1d(), transform2d(), or transform3d() objects.
  • as_transform1d(), as_transform2d(), and as_transform3d() cast objects to transform1d(), transform2d(), or transform3d() objects.
  • permute2d() and permute3d() transformation matrices permutes coordinate axes.
  • project1d(), project2d(), and project3d() create projection matrices.
  • reflect1d(), reflect2d() and reflect3d() create reflection affine transformation matrices.
  • rotate2d() and rotate3d() create rotation affine transformation matrices. rotate3d_to_AA() converts from 3D rotation matrix to axis-angle representation.
  • scale1d(), scale2d(), and scale3d() create scaling affine transformation matrices.
  • shear2d() and shear3d() create shearing affine transformation matrices.
  • translate1d(), translate2d(), and translate3d() create translation affine transformation matrices.

• {affiner} supports the following options settable by base::options():

  • affiner_angular_unit: The default for the unit argument used by angle() and as_angle(). The default for this option is “degrees”.
  • affiner_grid_unit: The default for the unit argument used by affine_settings(). The default for this option is inches.
  • These options can be queried with the convenience function affiner_options().