manifolds-0.4.1.0: Coordinate-free hypersurfaces

Copyright(c) Justus Sagemüller 2016
LicenseGPL v3
Maintainer(@) jsagemue $ uni-koeln.de
Stabilityexperimental
Portabilityportable
Safe HaskellNone
LanguageHaskell2010

Data.Manifold.Shade

Contents

Description

 

Synopsis

Shades

data Shade x Source

A Shade is a very crude description of a region within a manifold. It can be interpreted as either an ellipsoid shape, or as the Gaussian peak of a normal distribution (use http://hackage.haskell.org/package/manifold-random for actually sampling from that distribution).

For a precise description of an arbitrarily-shaped connected subset of a manifold, there is Region, whose implementation is vastly more complex.

Constructors

Shade 

Fields

_shadeCtr :: !(Interior x)
 
_shadeExpanse :: !(Metric' x)
 

pattern (:±) :: () => (WithField Manifold x, SimpleSpace (Needle x)) => Interior x -> [Needle x] -> Shade x infixl 6 Source

Span a Shade from a center point and multiple deviation-vectors.

data Shade' x Source

A “co-shade” can describe ellipsoid regions as well, but unlike Shade it can be unlimited / infinitely wide in some directions. It does OTOH need to have nonzero thickness, which Shade needs not.

Constructors

Shade' 

Fields

_shade'Ctr :: !(Interior x)
 
_shade'Narrowness :: !(Metric x)
 

(|±|) :: forall x. WithField EuclidSpace x => x -> [Needle x] -> Shade' x infixl 6 Source

Similar to ':±', but instead of expanding the shade, each vector restricts it. Iff these form a orthogonal basis (in whatever sense applicable), then both methods will be equivalent.

Note that '|±|' is only possible, as such, in an inner-product space; in general you need reciprocal vectors (Needle') to define a Shade'.

class IsShade shade where Source

Methods

shadeCtr :: Lens' (shade x) (Interior x) Source

Access the center of a Shade or a Shade'.

occlusion :: (PseudoAffine x, SimpleSpace (Needle x), s ~ Scalar (Needle x), RealFloat' s) => shade x -> x -> s Source

Check the statistical likelihood-density of a point being within a shade. This is taken as a normal distribution.

factoriseShade :: (PseudoAffine x, SimpleSpace (Needle x), PseudoAffine y, SimpleSpace (Needle y), Scalar (Needle x) ~ Scalar (Needle y)) => shade (x, y) -> (shade x, shade y) Source

coerceShade :: (Manifold x, Manifold y, LocallyCoercible x y) => shade x -> shade y Source

orthoShades :: (PseudoAffine x, SimpleSpace (Needle x), PseudoAffine y, SimpleSpace (Needle y), Scalar (Needle x) ~ Scalar (Needle y)) => shade x -> shade y -> shade (x, y) Source

ASCII version of '✠'.

linIsoTransformShade :: (SimpleSpace x, SimpleSpace y, Scalar x ~ Scalar y, Num' (Scalar x)) => (x +> y) -> shade x -> shade y Source

projectShade :: (Semimanifold x, Semimanifold y, Object (Affine s) (Interior x), Object (Affine s) (Interior y), SemiInner (Needle x), SemiInner (Needle y)) => Embedding (Affine s) (Interior x) (Interior y) -> shade y -> shade x Source

Squash a shade down into a lower dimensional space.

embedShade :: (Semimanifold x, Semimanifold y, Object (Affine s) (Interior x), Object (Affine s) (Interior y), SemiInner (Needle x), SemiInner (Needle y)) => Embedding (Affine s) (Interior x) (Interior y) -> shade x -> shade y Source

Include a shade in a higher-dimensional space. Notice that this behaves fundamentally different for Shade and Shade'. For Shade, it gives a “flat image” of the region, whereas for Shade' it gives an “extrusion pillar” pointing in the projection's orthogonal complement.

Lenses

shadeExpanse :: Lens' (Shade x) (Metric' x) Source

Construction

pointsShades :: (WithField PseudoAffine x, SimpleSpace (Needle x)) => [Interior x] -> [Shade x] Source

Attempt to find a Shade that describes the distribution of given points. At least in an affine space (and thus locally in any manifold), this can be used to estimate the parameters of a normal distribution from which some points were sampled. Note that some points will be “outside” of the shade, as happens for a normal distribution with some statistical likelyhood. (Use pointsCovers if you need to prevent that.)

For nonconnected manifolds it will be necessary to yield separate shades for each connected component. And for an empty input list, there is no shade! Hence the result type is a list.

pointsShade's :: forall x. (WithField PseudoAffine x, SimpleSpace (Needle x)) => [Interior x] -> [Shade' x] Source

pointsCovers :: forall x. (WithField PseudoAffine x, SimpleSpace (Needle x)) => [Interior x] -> [Shade x] Source

Like pointsShades, but ensure that all points are actually in the shade, i.e. if [Shade x₀ ex] is the result then metric (recipMetric ex) (p-x₀) ≤ 1 for all p in the list.

pointsCover's :: forall x. (WithField PseudoAffine x, SimpleSpace (Needle x)) => [Interior x] -> [Shade' x] Source

coverAllAround :: forall x s. (Fractional' s, WithField s PseudoAffine x, SimpleSpace (Needle x)) => Interior x -> [Needle x] -> Shade x Source

Evaluation

class Refinable m => LtdErrorShow m where Source

Minimal complete definition

showsPrecShade'_errorLtdC

Misc

(✠) :: (IsShade shade, PseudoAffine x, SimpleSpace (Needle x), PseudoAffine y, SimpleSpace (Needle y), Scalar (Needle x) ~ Scalar (Needle y)) => shade x -> shade y -> shade (x, y) infixl 5 Source

Combine two shades on independent subspaces to a shade with the same properties on the subspaces (see factoriseShade) and no covariance.

intersectShade's :: forall y. Refinable y => NonEmpty (Shade' y) -> Maybe (Shade' y) Source

class (WithField PseudoAffine y, SimpleSpace (Needle y)) => Refinable y where Source

Class of manifolds which can use Shade' as a basic set type. This is easily possible for vector spaces with the default implementations.

Minimal complete definition

Nothing

Methods

subShade' :: Shade' y -> Shade' y -> Bool Source

a subShade' b ≡ True means a is fully contained in b, i.e. from minusLogOcclusion' a p < 1 follows also minusLogOcclusion' b p < 1.

refineShade' :: Shade' y -> Shade' y -> Maybe (Shade' y) Source

Intersection between two shades.

convolveMetric :: Functor p => p y -> Metric y -> Metric y -> Metric y Source

If p is in a (red) and δ is in b (green), then p.+~^δ is in convolveShade' a b (blue).

Example: https://nbviewer.jupyter.org/github/leftaroundabout/manifolds/blob/master/test/ShadeCombinations.ipynb#shadeConvolutions

convolveShade' :: Shade' y -> Shade' (Needle y) -> Shade' y Source

Instances

Refinable ℝ⁰ Source 
Refinable Source 
Refinable ℝ⁴ Source 
Refinable ℝ³ Source 
Refinable ℝ² Source 
Refinable ℝ¹ Source 
(Refinable a, Refinable b, (~) * (Scalar (DualVector (DualVector (Needle b)))) (Scalar (DualVector (DualVector (Needle a))))) => Refinable (a, b) Source 
(SimpleSpace a, SimpleSpace b, Refinable a, Refinable b, (~) * (Scalar a) , (~) * (Scalar b) , (~) * (Scalar (DualVector a)) , (~) * (Scalar (DualVector b)) , (~) * (Scalar (DualVector (DualVector a))) , (~) * (Scalar (DualVector (DualVector b))) ) => Refinable (LinearMap a b) Source 

mixShade's :: forall y. (WithField Manifold y, SimpleSpace (Needle y)) => NonEmpty (Shade' y) -> Maybe (Shade' y) Source

Weakened version of intersectShade's. What this function calculates is rather the weighted mean of ellipsoid regions. If you interpret the shades as uncertain physical measurements with normal distribution, it gives the maximum-likelyhood result for multiple measurements of the same quantity.

dualShade :: forall x. (PseudoAffine x, SimpleSpace (Needle x)) => Shade x -> Shade' x Source

Misc

Shades

shadesMerge Source

Arguments

:: (WithField Manifold x, SimpleSpace (Needle x)) 
=>

How near (inverse normalised distance, relative to shade expanse) two shades must be to be merged. If this is zero, any shades in the same connected region of a manifold are merged.

-> [Shade x]

A list of n shades.

-> [Shade x]

mn shades which cover at least the same area.

Attempt to reduce the number of shades to fewer (ideally, a single one). In the simplest cases these should guaranteed cover the same area; for non-flat manifolds it only works in a heuristic sense.

pointsShades' :: forall x. (WithField PseudoAffine x, SimpleSpace (Needle x)) => Metric' x -> [x] -> [([x], Shade x)] Source

pseudoECM :: forall x p. (WithField PseudoAffine x, SimpleSpace (Needle x), Functor p) => p x -> NonEmpty x -> (x, ([x], [x])) Source

data WithAny x y Source

Essentially the same as (x,y), but not considered as a product topology. The Semimanifold etc. instances just copy the topology of x, ignoring y.

Constructors

WithAny 

Fields

_untopological :: y
 
_topological :: !x
 

Local data fit models

estimateLocalJacobian :: forall x y. (WithField Manifold x, Refinable y, SimpleSpace (Needle x), SimpleSpace (Needle y)) => Metric x -> [(Local x, Shade' y)] -> Maybe (Shade' (LocalLinear x y)) Source

data QuadraticModel x y Source

Constructors

QuadraticModel 

Fields

_quadraticModelOffset :: Interior y
 
_quadraticModel :: Shade (Needle y, (Needle x +> Needle y, Needle x `⊗〃+>` Needle y))
 

Differential equations

type DifferentialEqn x ð y = Shade (x, y) -> LocalDifferentialEqn x ð y Source

propagateDEqnSolution_loc :: forall x y ð. (WithField Manifold x, Refinable y, Geodesic (Interior y), WithField AffineManifold ð, Geodesic ð, SimpleSpace (Needle x), SimpleSpace (Needle ð)) => DifferentialEqn x ð y -> LocalDataPropPlan x (Shade' y, Shade' ð) (Shade' y) -> Maybe (Shade' y) Source

data LocalDataPropPlan x ym yr Source

Instances

(Show (Interior x), Show ym, Show yr, Show (Needle x)) => Show (LocalDataPropPlan x ym yr) Source 

Range interpolation

rangeOnGeodesic :: forall i m. (WithField PseudoAffine m, Geodesic m, SimpleSpace (Needle m), WithField IntervalLike i, SimpleSpace (Needle i)) => m -> m -> Maybe (Shade i -> Shade m) Source

Warning: This function never worked properly. Use rangeWithinVertices.

rangeWithinVertices :: forall s i m t. (RealFrac' s, WithField s PseudoAffine i, WithField s PseudoAffine m, Geodesic i, Geodesic m, SimpleSpace (Needle i), SimpleSpace (Needle m), AffineManifold (Interior i), AffineManifold (Interior m), Object (Affine s) (Interior i), Object (Affine s) (Interior m), Traversable t) => (Interior i, Interior m) -> t (i, m) -> Maybe (Shade i -> Shade m) Source