Overview of the Distribution Object
Description
List of Distribution object Methods
Examples
The Distribution object provides a general toolkit for dealing with distributions. A user can query properties of a Distribution object, compute associated quantities, and combine distributions in various ways. Some existing Maple utility functions such as indets, type, has,...etc are overloaded for use with the Distribution object.
A distribution in the differential-geometric sense is a specification of a subspace of tangent space at each point of a manifold M.
A Distribution object can be constructed via the Distribution constructor. To construct a Distribution object, see LieAlgebrasOfVectorFields[Distribution].
The Distribution object is an exported item in the LieAlgebrasOfVectorFields package. To construct and access a Distribution object, the LieAlgebrasOfVectorFields package must be loaded (i.e. with(LieAlgebrasOfVectorFields);). For more information, see Overview of the LieAlgebrasOfVectorFields package.
Once a Distribution object S has been constructed, each method in the Distribution object S can be accessed by either the short form command(S, otherArguments) or the long form S:-command(S, otherArguments).
A Distribution object is displayed (via its ModulePrint method) as a set of VectorField objects which form a basis for it at each point.
The following is a list of available commands in a Distribution object.
AreSameSpace
CauchyDistribution
Codimension
DChange
DerivedDistribution
Dimension
GetAnnihilator
GetSpace
GetVectorFields
Integrals
Intersection
IsIntegrable
IsInvariant
IsInvolutive
IsSubspace
IsTrivial
VectorSpaceSum
The following Maple builtins functions are extended so that they work for a Distribution object: type, has, hastype, indets, convert. See Distribution Object Overloaded Builtins for more detail.
with⁡LieAlgebrasOfVectorFields:
We first build vector fields associated with 3-d cylinder (2-dim x-y rotation, and z translation and uniform scaling)
X1≔VectorField⁡−y⁢Dx+x⁢Dy,space=x,y,z
X1≔−y⁢ⅆⅆx+x⁢ⅆⅆy
X2≔VectorField⁡Dz,space=x,y,z
X2≔ⅆⅆz
X3≔VectorField⁡z⁢Dz,space=x,y,z
X3≔z⁢ⅆⅆz
Σ≔Distribution⁡X1,X2,X3
Σ≔−y⁢ⅆⅆxx+ⅆⅆy,ⅆⅆz
Ω≔Distribution⁡VectorField⁡Dx,space=x,y,z
Ω≔ⅆⅆx
We can request the dimension of this distribution
Dimension⁡Σ
2
IsInvolutive⁡Σ
true
IsIntegrable⁡Σ
We can check if x-translation is subspace of Sigma
IsSubspace⁡Ω,Σ
false
Sum of these two distributions covers all (x,y,z) space.
VectorSpaceSum⁡Σ,Ω
ⅆⅆx,ⅆⅆy,ⅆⅆz
These two distribution don't intersect
Intersection⁡Σ,Ω
∅
The invariant of Sigma
Integrals⁡Σ
x2+y2
Finding other distributions..
CauchyDistribution⁡Σ
−y⁢ⅆⅆxx+ⅆⅆy,ⅆⅆz
DerivedDistribution⁡Σ
type⁡Σ,Distribution
See Also
LieAlgebrasOfVectorFields (Package overview)
LAVF (Object overview)
LieAlgebrasOfVectorFields[Distribution]
LieAlgebrasOfVectorFields[VectorField]
Download Help Document