MaplePrimes Questions

My instructor gave me the problem lim as x goes to 0 of ((2 + x)^3 +8)/x I can't figure out how to get the lim as x goes to, to show up.  There is no button for it in the expressions pallette like there is for things like the piecewise function. My instructor won't help me.  Is there a basic guide I can buy or something.  This software isn't very intuitive. 

Dear all,

 

Let me first explain a problem I've encountered when working with Maple 18 64 bit in Linux (Ubuntu 12.04). I've tried some things to solve it, but unfortunately without succes

When working with the DifferentialAlgebra package I'm encountering a problem concerning memory. Without going into details, I'm using the RosenfeldGroebner function (DifferentialAlgebra/RosenfeldGroebner) . After about 10 minutes of calculation or so, the computation stops with the error message

>> Error, (in DifferentialAlgebra:-RosenfeldGroebner) out of memory error

This particular error does not have a *help*-file, so no help there.

Now, I'm pretty bumped out because of this error, because I'm working on 16 GB RAM computer which is imo quite a lot. Moreover, I have the feeling, that Maple is not using the full capacity of memory. This, is because I was monitoring the memory during the computation (via the System monitor). Before I start the calculation: the memory usage is about 3.6 GiB (=22.8%). During the calculation it slowly rises until about 8GiB (50%) at which the computation stops and the above-mentioned error message pops up. So it looks there's a big part (about 7.5-8 GiB) of memory still available, but isn't used.

So my question is: What are the possibilities to solve this problem. What can I try to do to have more memory available to be able to do the calculation.


Of course I was looking into the possibilities myself. In my experience I found the information found on this forum and on the Maple help files confusing or not very helpful. Probably, because I have little knowledge of programming or computer architecture. Nevertheless I would like to know some things about it. So, iI'll  present what I tried to do:

- The command kernelopts('datalimit') returns the total amout of heap memory in kibibtyes that Maple may consume   
  In my aplication this is set to infinity. So I presume that this could not explain why the program stops at only 50% Memory usage

- The command kernelopts('bytesalloc') returns the total amount of bytes allocated by Maple kernel. This value cannot be set.  Does this attribute pose a limit on calculations or is this  the amount of memory used by the Maple 'overhead'?   
In my application the value of this attribute is 8781824 bytes, so that's about 8 MB. I suppose it is not related to the problem I'm having, or is it? 

The command kernelopts('stacklimit') returns The total amount of stack space avilable. In my application this was initially set to 8160 kibityes. I've changed this to 8160000000, wel beyond the availble memory. I would think that this now would not anymore present a limit on the memory usage.

The command kernelopts('jvmheaplimit') returns the maximum amout of heap memory for the Java virtual machine. I presume this is the maximum amout of memory for the visiualisation part of Maple (is this correct) In my application this was initially set to 65536 kiB. I've changed this to 65536000000 kBib which is well above the available memroy. I would think that this now would not anymore present a limit on the memory usage

The command   kernelopts('cacheclearlimit'); returns the memory for maintaining temporary elements in cache. In my application this was initially 524288 kiB, but i changed this to 524288000000. I would think that, again, the limit on the memory usage would be gone.

I tried the calculation again with the mentioned changes in the memory attributes. Unfortunately, the error message *out of memory error* still popped up at about 50% memory usage.

Did I overlook something?? What can I do?? Is there actually that I can do? Where should I look?

Many thanks !!

The installation / activation went without trouble. The problem occurs when I want to start Maple. The splash screen shows up with a blue loading bar and that's it. It just keeps loading, sometimes it gets to the end but nothing more. Taskmanager shows a CPU usage of +/- 15%. I searched the net for answers but I only found two similar situations. One was due to the java heap size and another one due to tcp/ip problems. I checked both but the problem still persists. I really need Maple for my courses and you guys are my last resort. I'm running it on win7 64bit and I tried both 32 and 64bit Maple.

input : a*b+a*c

output: (a+b)*(a+c)

convert sum of product to product of sum

how to find the homomorphism between prime ideal and space?

how to find the homomorphism between prime ideal and distributive lattice?

 

which homomorphism result in space if given prime ideal?

Hi, 

I'm trying to set up the dirac algebra using the Physics package in maple 18. There are dirac gamma matricies (Dgamma) already specified, but I can't seem to manipulate their commutation relations. 

So I've tried building my own: 

restart;
with(Physics);

Setup(noncommutativeprefix = {gamma});

g[1] := gamma[1]; g[2] := gamma[2]; g[3] := gamma[3]; g[4] := gamma[0];

InverseMetric := rhs(g_[`~mu`, `~nu`, matrix])

Algebra :=  (a, b) -> %AntiCommutator(g[a], g[b]) = 2*InverseMetric[a, b];

Rules := Matrix(4, 4, Algebra);

Setup(algebrarules = Rules);

Error, (in Physics:-Setup) unable to set AntiCommutator(gamma[0], gamma[1]) = 0 because, taking into account {AntiCommutator(gamma[0], gamma[0]) = 2}, we would have gamma[0] and gamma[0] anticommutative and AntiCommutator(gamma[0], gamma[0]) <> 0

It seems like Maple can't handle the Dirac Algebra? Or have I done something obviously wrong?

Any help is appreciated. 

Thanks

Find the smallest number N such that

π2/6 − Σ (from n=1 to N) 1/n< 0.001

using Maple commands.

Successively transform the expression x + y + z into x ∗ y ∗ z and [x, y, z], using Maple commands.

Hello,

I am going to model a statically balanced mechanism by using zero free length spring in MapleSim. In path Multibody> Force and Moments>, there is a Translational Spring and Damper which I can use, and I just enter zero length for spring unstreched length. In physical model, zero free length spring never get zero length because of the existing coils, but in MapleSim it reaches zero during simulation. Does anyone here know how can I model zero free length springs?

Thanks

How to find the coefficients of the terms diff(eta1(xi1),xi1)*diff(eta2(xi2),xi2)eta1(xi1)^2,...

how to save the session of maple worksheet so that no need to calculate again after restart computer

after calculated 70 million result for a long time, how to save the result and session so that no need to recalculate again?

Hi,

I use Maple on my laptop computer (windows 8.1) with a small screen. My problem is that the text in the menus, palettes, plots etc. are so small so I can´t read it. I have set Large toolbar icons under the menu tools-options-interface and I use the zoom buttom on the toolbar but this only magnify the text in a document. I also use the magnifying glass in windows, but I find it very inflexible. Is there any better solution to this problem?

Kind Regards

Leif Jonson

Hello

I have done this question again but i didnt get an answer.So does anyone know how i can substitute the following variables to an equation?I tried to create a list but i dont know how the variables can be substituted in the right place.data.docxdata.docxalfaeq.mw

Thanks

Contour lines must be ordinary circles. In fact, we get:

plots[contourplot](1/(x^2+y^2), x=-1..1, y=-1..1);

 

 

If we use the additional options, the result is even worse:

plots[contourplot](1/(x^2+y^2), x=-1..1,y=-1..1, numpoints=10000);

 

 

Hello i want to sort according to u derivatives (k) system.  And finding determining equations system and solving this system. Thank you very much.  

restart

with(PDEtools)

[CanonicalCoordinates, ChangeSymmetry, CharacteristicQ, CharacteristicQInvariants, ConservedCurrentTest, ConservedCurrents, ConsistencyTest, D_Dx, DeterminingPDE, Eta_k, Euler, FromJet, InfinitesimalGenerator, Infinitesimals, IntegratingFactorTest, IntegratingFactors, InvariantEquation, InvariantSolutions, InvariantTransformation, Invariants, Laplace, Library, PDEplot, PolynomialSolutions, ReducedForm, SimilaritySolutions, SimilarityTransformation, Solve, SymmetrySolutions, SymmetryTest, SymmetryTransformation, TWSolutions, ToJet, build, casesplit, charstrip, dchange, dcoeffs, declare, diff_table, difforder, dpolyform, dsubs, mapde, separability, splitstrip, splitsys, undeclare]

(1)

U := diff_table(u(x, y, t))

table( [(  ) = u(x, y, t) ] )

(2)

declare(U[])

u(x, y, t)*`will now be displayed as`*u

(3)

pde := diff(U[t]-(3/2)*U[x]-6*U[]^2*U[x]+U[x, x, x], x)+U[y, y] = 0

diff(diff(u(x, y, t), t), x)-(3/2)*(diff(diff(u(x, y, t), x), x))-12*u(x, y, t)*(diff(u(x, y, t), x))^2-6*u(x, y, t)^2*(diff(diff(u(x, y, t), x), x))+diff(diff(diff(diff(u(x, y, t), x), x), x), x)+diff(diff(u(x, y, t), y), y) = 0

(4)

NULL

w := phi(x, y, t, U[])

phi(x, y, t, u(x, y, t))

(5)

w*(-12*U[x]^2-12*U[]*U[x, x])+12*w*U[x]^2+12*U[]*w*U[x, x]+(diff(w, x, x))*(-3/2-6*U[]^2)+diff(diff(w, t), x)+diff(w, y, y)+diff(w, x, x, x, x)-lambda*(diff(U[t]-(3/2)*U[x]-6*U[]^2*U[x]+U[x, x, x], x)+U[y, y])

-lambda*(diff(diff(u(x, y, t), t), x)-(3/2)*(diff(diff(u(x, y, t), x), x))-12*u(x, y, t)*(diff(u(x, y, t), x))^2-6*u(x, y, t)^2*(diff(diff(u(x, y, t), x), x))+diff(diff(diff(diff(u(x, y, t), x), x), x), x)+diff(diff(u(x, y, t), y), y))+(D[1, 1, 1, 1](phi))(x, y, t, u(x, y, t))+(D[1, 1, 1, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x))+((D[1, 1, 1, 4](phi))(x, y, t, u(x, y, t))+(D[1, 1, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x)))*(diff(u(x, y, t), x))+(D[1, 1, 4](phi))(x, y, t, u(x, y, t))*(diff(diff(u(x, y, t), x), x))+((D[1, 1, 1, 4](phi))(x, y, t, u(x, y, t))+(D[1, 1, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x))+((D[1, 1, 4, 4](phi))(x, y, t, u(x, y, t))+(D[1, 4, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x)))*(diff(u(x, y, t), x))+(D[1, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(diff(u(x, y, t), x), x)))*(diff(u(x, y, t), x))+2*((D[1, 1, 4](phi))(x, y, t, u(x, y, t))+(D[1, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x)))*(diff(diff(u(x, y, t), x), x))+(D[1, 4](phi))(x, y, t, u(x, y, t))*(diff(diff(diff(u(x, y, t), x), x), x))+((D[1, 1, 1, 4](phi))(x, y, t, u(x, y, t))+(D[1, 1, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x))+((D[1, 1, 4, 4](phi))(x, y, t, u(x, y, t))+(D[1, 4, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x)))*(diff(u(x, y, t), x))+(D[1, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(diff(u(x, y, t), x), x))+((D[1, 1, 4, 4](phi))(x, y, t, u(x, y, t))+(D[1, 4, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x))+((D[1, 4, 4, 4](phi))(x, y, t, u(x, y, t))+(D[4, 4, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x)))*(diff(u(x, y, t), x))+(D[4, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(diff(u(x, y, t), x), x)))*(diff(u(x, y, t), x))+2*((D[1, 4, 4](phi))(x, y, t, u(x, y, t))+(D[4, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x)))*(diff(diff(u(x, y, t), x), x))+(D[4, 4](phi))(x, y, t, u(x, y, t))*(diff(diff(diff(u(x, y, t), x), x), x)))*(diff(u(x, y, t), x))+3*((D[1, 1, 4](phi))(x, y, t, u(x, y, t))+(D[1, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x))+((D[1, 4, 4](phi))(x, y, t, u(x, y, t))+(D[4, 4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x)))*(diff(u(x, y, t), x))+(D[4, 4](phi))(x, y, t, u(x, y, t))*(diff(diff(u(x, y, t), x), x)))*(diff(diff(u(x, y, t), x), x))+3*((D[1, 4](phi))(x, y, t, u(x, y, t))+(D[4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x)))*(diff(diff(diff(u(x, y, t), x), x), x))+(D[4](phi))(x, y, t, u(x, y, t))*(diff(diff(diff(diff(u(x, y, t), x), x), x), x))+(D[2, 2](phi))(x, y, t, u(x, y, t))+(D[2, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), y))+((D[2, 4](phi))(x, y, t, u(x, y, t))+(D[4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), y)))*(diff(u(x, y, t), y))+(D[4](phi))(x, y, t, u(x, y, t))*(diff(diff(u(x, y, t), y), y))+(D[1, 3](phi))(x, y, t, u(x, y, t))+(D[3, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x))+((D[1, 4](phi))(x, y, t, u(x, y, t))+(D[4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x)))*(diff(u(x, y, t), t))+(D[4](phi))(x, y, t, u(x, y, t))*(diff(diff(u(x, y, t), t), x))+((D[1, 1](phi))(x, y, t, u(x, y, t))+(D[1, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x))+((D[1, 4](phi))(x, y, t, u(x, y, t))+(D[4, 4](phi))(x, y, t, u(x, y, t))*(diff(u(x, y, t), x)))*(diff(u(x, y, t), x))+(D[4](phi))(x, y, t, u(x, y, t))*(diff(diff(u(x, y, t), x), x)))*(-3/2-6*u(x, y, t)^2)+12*u(x, y, t)*phi(x, y, t, u(x, y, t))*(diff(diff(u(x, y, t), x), x))+12*phi(x, y, t, u(x, y, t))*(diff(u(x, y, t), x))^2+phi(x, y, t, u(x, y, t))*(-12*(diff(u(x, y, t), x))^2-12*u(x, y, t)*(diff(diff(u(x, y, t), x), x)))

(6)

k := simplify(%)

-(3/2)*(D[1, 1](phi))(x, y, t, u(x, y, t))+(D[1, 3](phi))(x, y, t, u(x, y, t))+(D[2, 2](phi))(x, y, t, u(x, y, t))+(D[1, 1, 1, 1](phi))(x, y, t, u(x, y, t))+4*(D[1, 1, 1, 4](phi))(x, y, t, u(x, y, t))*(D[1](u))(x, y, t)+6*(D[1, 1, 4](phi))(x, y, t, u(x, y, t))*(D[1, 1](u))(x, y, t)+4*(D[1, 4](phi))(x, y, t, u(x, y, t))*(D[1, 1, 1](u))(x, y, t)+(D[4](phi))(x, y, t, u(x, y, t))*(D[1, 1, 1, 1](u))(x, y, t)+2*(D[2, 4](phi))(x, y, t, u(x, y, t))*(D[2](u))(x, y, t)+(D[4](phi))(x, y, t, u(x, y, t))*(D[2, 2](u))(x, y, t)+(D[3, 4](phi))(x, y, t, u(x, y, t))*(D[1](u))(x, y, t)+(D[4](phi))(x, y, t, u(x, y, t))*(D[1, 3](u))(x, y, t)-3*(D[1, 4](phi))(x, y, t, u(x, y, t))*(D[1](u))(x, y, t)-(3/2)*(D[4](phi))(x, y, t, u(x, y, t))*(D[1, 1](u))(x, y, t)-lambda*(D[1, 3](u))(x, y, t)+(3/2)*lambda*(D[1, 1](u))(x, y, t)-lambda*(D[1, 1, 1, 1](u))(x, y, t)-lambda*(D[2, 2](u))(x, y, t)+6*(D[1, 1, 4, 4](phi))(x, y, t, u(x, y, t))*(D[1](u))(x, y, t)^2+4*(D[1, 4, 4, 4](phi))(x, y, t, u(x, y, t))*(D[1](u))(x, y, t)^3+(D[4, 4, 4, 4](phi))(x, y, t, u(x, y, t))*(D[1](u))(x, y, t)^4+3*(D[4, 4](phi))(x, y, t, u(x, y, t))*(D[1, 1](u))(x, y, t)^2+(D[4, 4](phi))(x, y, t, u(x, y, t))*(D[2](u))(x, y, t)^2+(D[3](u))(x, y, t)*(D[1, 4](phi))(x, y, t, u(x, y, t))-(3/2)*(D[4, 4](phi))(x, y, t, u(x, y, t))*(D[1](u))(x, y, t)^2-6*(D[1, 1](phi))(x, y, t, u(x, y, t))*u(x, y, t)^2+12*lambda*u(x, y, t)*(D[1](u))(x, y, t)^2+6*lambda*u(x, y, t)^2*(D[1, 1](u))(x, y, t)+12*(D[1](u))(x, y, t)*(D[1, 4, 4](phi))(x, y, t, u(x, y, t))*(D[1, 1](u))(x, y, t)+6*(D[1](u))(x, y, t)^2*(D[4, 4, 4](phi))(x, y, t, u(x, y, t))*(D[1, 1](u))(x, y, t)+4*(D[1](u))(x, y, t)*(D[4, 4](phi))(x, y, t, u(x, y, t))*(D[1, 1, 1](u))(x, y, t)+(D[3](u))(x, y, t)*(D[4, 4](phi))(x, y, t, u(x, y, t))*(D[1](u))(x, y, t)-12*(D[1, 4](phi))(x, y, t, u(x, y, t))*(D[1](u))(x, y, t)*u(x, y, t)^2-6*(D[4, 4](phi))(x, y, t, u(x, y, t))*(D[1](u))(x, y, t)^2*u(x, y, t)^2-6*(D[4](phi))(x, y, t, u(x, y, t))*(D[1, 1](u))(x, y, t)*u(x, y, t)^2

(7)

frontend(coeff, [k, U[x]^2]);

0

(8)

frontend(coeff, [k, U[x]*U[x, x]])

Error, invalid input: coeff received O*O, which is not valid for its 2nd argument, x

 

NULL


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