DChange
perform change of variables in a vector field or a one-form.
Calling Sequence
Parameters
Description
Examples
Compatibility
DChange (tr, obj, newVars, options)
dchange (tr, obj, newVars, options)
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
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.
with⁡LieAlgebrasOfVectorFields:
R≔VectorField⁡−y,x,x,y
R≔−y⁢ⅆⅆx+x⁢ⅆⅆy
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
We can further simplify this VectorField object, using the overloaded builtin simplify:
simplify⁡P
ⅆⅆθ
These two vector fields are on different spaces.
GetSpace⁡R
x,y
GetSpace⁡P
r,θ
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
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