DChange - Maple Help
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DChange

perform change of variables in a vector field or a one-form.

 

Calling Sequence

Parameters

Description

Examples

Compatibility

Calling Sequence

DChange (tr, obj, newVars, options)

dchange (tr, obj, newVars, options)

Parameters

tr

-

set of equations corresponding to the transformation from the old variables on the left-hand side of the equations to the new variables on the right-hand side.

obj

-

a VectorField or OneForm object

newVars

-

a list of new variable names

options

-

optional arguments that will be passed down to PDEtools[dchange] command

Description

• 

The DChange method performs changes of variables in a VectorField or OneForm object.

• 

This method returns a new VectorField or OneForm object living on the space specified by newVars.

• 

The name dchange is provided as an alias.

• 

This DChange method is based on the existing Maple function PDEtools[dchange].

• 

These methods are associated with the VectorField and OneForm objects. For more detail see Overview of the VectorField object, Overview of the OneForm object.

Examples

> 

with⁡LieAlgebrasOfVectorFields:

 

> 

R≔VectorField⁡−y,x,x,y

R≔−y⁢ⅆⅆx+x⁢ⅆⅆy

(1)

 

Change variables to use polar coordinates (r,theta):

> 

P≔DChange⁡x=r⁢cos⁡θ,y=r⁢sin⁡θ,R,r,θ

P≔cos⁡θ2+sin⁡θ2⁢ⅆⅆθ

(2)

 

We can further simplify this VectorField object, using the overloaded builtin simplify:

> 

simplify⁡P

ⅆⅆθ

(3)

These two vector fields are on different spaces.

> 

GetSpace⁡R

x,y

(4)
> 

GetSpace⁡P

r,θ

(5)

Compatibility

• 

The DChange command was introduced in Maple 2020.

• 

For more information on Maple 2020 changes, see Updates in Maple 2020.

See Also

VectorField (Object overview)

OneForm (Object overview)

LieAlgebrasOfVectorFields[VectorField]

LieAlgebrasOfVectorFields[OneForm]

GetSpace

PDEtools[dchange]

VectorField Builtins