# PlaneGeometry 1.6.0 (2023-08-07)

• New functions `LineFromInterceptAndSlope` and `LineFromEquation`.

• New R6 class `Hyperbola`.

# PlaneGeometry 1.5.1 (2023-06-23)

• Unit tests and vignette chunks are now skipped if dependencies are missing.

# PlaneGeometry 1.5.0 (2023-06-17)

• The `path` method of the `Ellipse` class gains an argument `outer` allowing to choose whether the path approximating the ellipse will be interior or exterior (thanks to Duncan Murdoch for the help).

• New method `perimeter` for the `Ellipse` class; it returns the perimeter of the ellipse.

• New methods for the `Triangle` class: `perimeter` and `outerSoddyCircle` (beware - this circle possibly has a negative radius).

• New example in the vignette.

# PlaneGeometry 1.4.0 (2023-05-19)

• New function `maxAreaInscribedCircle`, to compute the circle inscribed in a convex polygon with maximum area. This optimization problem is solved with the help of the CVXR package.

• New function `maxAreaInscribedEllipse`, to compute the ellipse inscribed in a convex polygon with maximum area. This optimization problem is solved with the help of the CVXR package.

# PlaneGeometry 1.3.1 (2022-01-13)

New function `fitEllipse`, to fit an ellipse to a set of points. It uses the fitConic package.

# PlaneGeometry 1.3.0 (2021-12-21)

• Fixed the `isEqual` method of the `Line` class.

• Fixed Möbius raised at the power 0.

• Added the method `fixedPoints` to the `Mobius` class.

• New function `MobiusMappingCircle`, which returns a Möbius transformation mapping a given circle to another given circle.

• New function `MobiusSwappingTwoPoints`, returning a Möbius transformation swapping two given points.

• New function `EllipseFromThreeBoundaryPoints`, returning the smallest area ellipse passing through three given boundary points.

• New function `EllipseFromFociAndOnePoint`, returning the ellipse with given foci and a given point on its boundary.

• New function attached to the `Triangle` class: `MandartInellipse`, which returns the Mandart inellipse of the triangle.

• New function attached to the `Triangle` class: `hexylTriangle`, which returns the hexyl triangle of the triangle.

• New function attached to the `Triangle` class: `isogonalConjugate`, which returns the isogonal conjugate of a point with respect to the triangle.

• New examples in the vignette: an illustration of inversions, Schottky circles, modular tessellation, Apollonian gasket, and Malfatti gasket.

# PlaneGeometry 1.2.0 (2020-08-06)

• New methods for `Ellipse` class: `theta2t`, `pointFromEccentricAngle`, `normal`.

• New example in the vignette, the elliptical billiard.

# PlaneGeometry 1.1.0 (2020-02-24)

• Bug fixed: the function `inversionSwappingTwoCircles` did not work for all cases.

• New functions: `inversionFromCircle`, `midCircles`, `CircleAB`.

• New methods for `Circle` class: `tangentsThroughExternalPoint`, `isOrthogonal`, `angle`.

• New methods for `Triangle` class: `symmedialTriangle`, `symmedianPoint`, `BrocardCircle`, `BrocardPoints`, `LemoineCircleI/II/III`, `LemoineTriangle`, `ParryCircle`, `SteinerEllipse`, `SteinerInellipse`, `pointToTrilinear`, `pedalTriangle`, `CevianTriangle`.

• New methods for `Line` class: `distance`, `parallel`.

• New methods for `Mobius` class: `power`, `gpower`.

First release.