sand15

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5 years, 83 days

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These are questions asked by sand15

Hi everybody, 

Only weights of type "numeric" can be used in a weighted graph (package GraphTheory) .
Is it possible to bypass this limitation and affect an infinite weight to an edge ?
If not possible, does it exist some "highest numeric value" in Maple I could use instead ?
(the trick of a very high value doesn't suit me)

Subsidiary question : is it possible to change the printing format for those weights ?
For instance   GraphTheory:-SetEdgeWeight(MyGraph, MyEdge, 123.4) plots the value 123 on edfe MyEdge

Thanks in advance

Hi everybody,
 

I write a worksheet which contains thesimple code provided in ?Maplets[Button] :

with(Maplets[Elements]):
maplet := Maplet(["Select one:", ......]) 
Maplets[Display](maplet):


As mentioned in ?MapleViewer it is possible to export a worksheet in a .maplet file (I use Windows 7) and to execute it by double clicking on the corresponding icon.
I proceeded as explained in the help page
But double clicking does not work with me : a "User Interface Customization System" window opens and shuts after a few seconds without displaying the expected maplet 

(right click + open with and select mapleviewer.exe shows that mapleviewer.exe does exist, so the issue does not likely come from an incomplete Maple installation).

I tried a few variants of the worksheet, such that
with(Maplets[Elements]):
Maplets[Display](Maplet(["Select one:", ......])  ):

or even
Maplets[Display](Maplet(["Select one:", ......])  ):

But it keeps getting bad
Could you please help me to fix this ?

TIA

Hi everyone

I would like to unassign all  'user' variables but some of them.
More precisely, if 

  • MyVars := anames('user')
  • and KeepThese := {...} is some subset (manually constructed) of MyVars

I was thinking to something like
for k in MyVars minus KeepThese  do
   k := 'k'   # or k := unassign('k')
end do;

... which (obviously) does not work as desired because 'k' refers to the variable of name k and not to the variable k represents.

How is it possible to fix this ?

Great thanks in advance

Hello everybody,

I develop a simulator of dynamical systems governed by ODE systems.
Thanks to intensive upstream testing I have already identified some "methods" that work well on some classes of systems and poorly for some others (here "method" is intented in the sense of dsolve(..., numeric, method=...)), but it is rather difficult to know in advance if method A will perform well or not, or if method B could be better ...
This is very classical.

On the other side, people this simulator is designed for, do not want to use directly MAPLE to  choose a method among all those it proposes,nor to adjust the many parameters some methods can have

The idea I have in mind is to facilitate their choice by developing a specific Maplet. This Maplet could take as a model the pane dsolve[interactive]() opens when you select the numerical solving strategy.
As far as possible I would like to customize this pane for it be closer to our own needs (specific options sholud be proposed as well as personal help pages)

So my questions:

1/  Is the corresponding code avaliable (I failed to find it while using showstat) ?
1'/ Incidentally, even if this simulator is designed for internal purposes alone, is there some kind of copyright or usage limitations of the code above ?
2/ Is it possible to obtain the list of all the avaliable methods (euler, rk4, gear, ...) without without constructing it manually ?
3/ Once a method is choosen, is it possible to obtain the list of all its options (here again without without constructing it manually) ?

Maybe a quite unusual request on this site but I would greatly appreciate any answer

Thanks in advance

Hi everybody

I have two tables, namely A and B, the entries of wich can also be tables ... and so on.
These two tables have the same structure in the following sense :

Viewing A or B as tree graphs GA and GB :

  1.  the set of the names of the vertices of GA is identical to the set of the names of the vertices of GB
  2. GA and GB have the same connectivities

For instance A and B below share the same structure
A := table([x=table([u=1]), y=table([v=table([p=2]), w=3]) )]
B := table([ x=table([u=4]), y=table([v=table([p=12]), w=3]) )]

But not do A and C
C := table([x=table([u=1]), y=table(v=2, w=3]) )]


Let p(s) some path in GA from its root to some terminal leaf s.
B being "structurally identical" to A, GB also contains p(s)
Returning to the original tables, p(s) corresponds to a multi-index [k1][k2]...[kn] and the "value" of s is then given by A [k1][k2]...[kn]) or, symbolically A[p(s)]

I adopt this definition for "A = B" :
A is said to be equal to B iif the entry of A[p(s)] equals B[p(s)] for all the terminal leaves s
(here equals is intended in the "classical" senses, ie 3=3, {1,2}={2,1}, ...)
 

How can I check if "A=B" in the following sense ?

Thanks in advance

PS : Keeping in mind the analogy between A and GA, I have written a recursive procedure to check if A=B. But it is rather lengthy and I wondered if there could exist some Maple function to do this test ?


 

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