Maintainer | diagrams-discuss@googlegroups.com |
---|---|

Safe Haskell | None |

Basic types for two-dimensional Euclidean space.

- data R2 = R2 !Double !Double
- r2 :: (Double, Double) -> R2
- unr2 :: R2 -> (Double, Double)
- mkR2 :: Double -> Double -> R2
- r2Iso :: Iso' R2 (Double, Double)
- type P2 = Point R2
- p2 :: (Double, Double) -> P2
- mkP2 :: Double -> Double -> P2
- unp2 :: P2 -> (Double, Double)
- p2Iso :: Iso' P2 (Double, Double)
- type T2 = Transformation R2
- data Angle
- rad :: Iso' Angle Double
- turn :: Iso' Angle Double
- deg :: Iso' Angle Double
- fullTurn :: Angle
- fullCircle :: Angle
- angleRatio :: Angle -> Angle -> Double
- (@@) :: b -> Iso' a b -> a

# 2D Euclidean space

The two-dimensional Euclidean vector space R^2. This type is intentionally abstract.

- To construct a vector, use
`r2`

, or`^&`

(from Diagrams.Coordinates):

r2 (3,4) :: R2 3 ^& 4 :: R2

Note that Diagrams.Coordinates is not re-exported by Diagrams.Prelude and must be explicitly imported.

- To construct the vector from the origin to a point
`p`

, use`p`

.`.-.`

`origin`

- To convert a vector
`v`

into the point obtained by following`v`

from the origin, use

.`origin`

`.+^`

v - To convert a vector back into a pair of components, use
`unv2`

or`coords`

(from Diagrams.Coordinates). These are typically used in conjunction with the`ViewPatterns`

extension:

foo (unr2 -> (x,y)) = ... foo (coords -> x :& y) = ...

Eq R2 | |

Fractional R2 | |

Num R2 | |

Ord R2 | |

Read R2 | |

Show R2 | |

Typeable R2 | |

Transformable R2 | |

Wrapped R2 | Lens wrapped isomorphisms for R2. |

HasBasis R2 | |

VectorSpace R2 | |

InnerSpace R2 | |

AdditiveGroup R2 | |

HasY P2 | |

HasY R2 | |

HasX P2 | |

HasX R2 | |

Coordinates R2 | |

Rewrapped R2 R2 | |

Traced (FixedSegment R2) | |

Traced (Trail R2) | |

Traced (Path R2) | |

Traced (Segment Closed R2) | |

Renderable (Path R2) b => TrailLike (QDiagram b R2 Any) |

unr2 :: R2 -> (Double, Double)Source

Convert a 2D vector back into a pair of components. See also `coords`

.

Points in R^2. This type is intentionally abstract.

- To construct a point, use
`p2`

, or`^&`

(see Diagrams.Coordinates):

p2 (3,4) :: P2 3 ^& 4 :: P2

- To construct a point from a vector
`v`

, use

.`origin`

`.+^`

v - To convert a point
`p`

into the vector from the origin to`p`

, use`p`

.`.-.`

`origin`

- To convert a point back into a pair of coordinates, use
`unp2`

, or`coords`

(from Diagrams.Coordinates). It's common to use these in conjunction with the`ViewPatterns`

extension:

foo (unp2 -> (x,y)) = ... foo (coords -> x :& y) = ...

unp2 :: P2 -> (Double, Double)Source

Convert a 2D point back into a pair of coordinates. See also `coords`

.

type T2 = Transformation R2Source

Transformations in R^2.

# Angles

Angles can be expressed in a variety of units. Internally, they are represented in radians.

rad :: Iso' Angle DoubleSource

The radian measure of an `Angle`

`a`

can be accessed as ```
a
^. rad
```

. A new `Angle`

can be defined in radians as `pi @@ rad`

.

turn :: Iso' Angle DoubleSource

The measure of an `Angle`

`a`

in full circles can be accessed as
`a ^. turn`

. A new `Angle`

of one-half circle can be defined in as
`1/2 @@ turn`

.

deg :: Iso' Angle DoubleSource

The degree measure of an `Angle`

`a`

can be accessed as ```
a
^. deg
```

. A new `Angle`

can be defined in degrees as ```
180 @@
deg
```

.

Deprecated synonym for `fullTurn`

, retained for backwards compatibility.

angleRatio :: Angle -> Angle -> DoubleSource

Calculate ratio between two angles.