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DifferentialGeometry

  

RemoveFrame

  

remove a frame from a Maple session

 

Calling Sequence

Parameters

Description

Examples

Calling Sequence

RemoveFrame(M)

Parameters

M

-

an unassigned Maple name or a string

Description

• 

Remove a previously defined frame M from the current Maple session.  All protected variables and frame and coframe labels associated with the frame M become unassigned and unprotected.  The command returns the number of frames that remain available.

• 

If the current frame is M and M is removed, then the current frame defaults to the first frame in an alphabetic listing of all remaining defined frames.

• 

This command is part of the DifferentialGeometry package, and so can be used in the form RemoveFrame(...) only after executing the command with(DifferentialGeometry).  It can always be used in the long form DifferentialGeometry:-RemoveFrame.

Examples

withDifferentialGeometry:

 

Example 1.

Create a pair of manifolds.

DGsetupx,y,M,verbose:

The following coordinates have been protected:

x,y

The following vector fields have been defined and protected:

_DGvector,M,,1,1,_DGvector,M,,2,1

The following differential 1-forms have been defined and protected:

_DGform,M,1,1,1,_DGform,M,1,2,1

(1)

DGsetupu,v,N,verbose

The following coordinates have been protected:

u,v

The following vector fields have been defined and protected:

_DGvector,N,,1,1,_DGvector,N,,2,1

The following differential 1-forms have been defined and protected:

_DGform,N,1,1,1,_DGform,N,1,2,1

frame name: N

(2)

The command DGinfo can return a list of all defined manifolds, adapted frames, Lie algebras, etc. - everything created by DGsetup.

Tools:-DGinfoFrameNames

M,N

(3)

Note that u is protected and D_u is assigned.

typeu,protected

true

(4)

lprintD_u

_DG([["vector", N, []], [[[1], 1]]])

 

Now remove the frame N.

RemoveFrameN

1

(5)

The frame N no longer shows up in the list of defined frames.

Tools:-DGinfoFrameNames

M

(6)

The current frame is now M.

Tools:-DGinfoCurrentFrame

M

(7)

Also, u is no longer protected and D_u is unassigned.

typeu,protected

false

(8)

lprintD_u

D_u

M > 

See Also

DifferentialGeometry

ChangeFrame

DGinfo

DGsetup