marekszpak

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10 years, 48 days

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These are questions asked by marekszpak

Is there any webpage like Wolfram Library Archive but with Maple related resources? I've missed something or everything goes to mapleprimes? 

Hi!

I have a problem recently with running RootFinding:-Isolate inside a procedure which is run on threads. I have many polynomial systems to treat so I would like to balance computations between cores. Unfortunately, my code always breaks computation kernel with the error:

java.lang.NullPointerException

at com.maplesoft.mathdoc.model.WmiModelLock.acquireLock(Unknown Source)
at com.maplesoft.mathdoc.model.WmiModelLock.writeLock(Unknown Source)
at com.maplesoft.worksheet.connection.WmiOutputUpdateBuffer$UpdateSynchronizer.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

 

I wrote a small example below

f:=proc(n)

   local i;

   for i from 1 to n do
    try

      RootFinding:-Isolate([a^2+b^2-1/3c^2,a^2-1/3b^2+c^2-1/3,a^2-1/3b^2-1/3c^2+1],[a,b,c]):

   catch "":
     next:
   end try:
  end do:
end proc:

Threads:-Task:-Start ( null, Task[f,10000], Task[f,10000], Task[f,10000]);

 

I have no much of experiences with threads in Maple so I would not be surprise if I'm trying to do something completely wrong here. Any hint or advice will be appreciate. 

Hello,

Today I've playied a bit with CellDecomposition from the RootFinding package and for one of the systems with which I've playied I got an error which seems to me to be a bug related.

In particular, 

with(RootFinding[Parametric]):

m := CellDecomposition([x^3-y^2 = 0, x^2+y^2-1 < 0], [x, y])

Error, (in RootFinding:-Parametric:-CellDecomposition) Segmentation Violation occurred in external routine

 

Did I make a mistake somewhere or Maple 2015.1 faild?

Maybe a bit strange question (just exploring Maple and a new topic), but is there a way to use CylindricalAlgebraicDecompose with a rational functions, eg 1/x, where eg is x an integer? I tried to use it but always ended up with:

 

Error, invalid input: RegularChains:-SemiAlgebraicSetTools:-CylindricalAlgebraicDecompose expects its 1st argument, F, to be of type Or(list(list(Or(polynom(rational), polynom(rational) = polynom(rational), polynom(rational) <> polynom(rational), polynom(rational) <= polynom(rational), polynom(rational) < polynom(rational)))), list(polynom(rational))), but received [1/x = x, polynom(rational)]

Hi! I just started to use Maple and I play with some of its functions. I have seen in examples related to RegularChain package an output like  [regular_chain, [[-1, -1], [0, 0]]] and I wonder how I should read it. Thanks for any help and sorry if my question is very basic.

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