Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

Hi,

Please can you give me a hand with numerical solving and visualising the integral equation with stochastic term B(t), using quadrature method ?

I had a look at the "stochastic" package by Sasha Cyganowski

Look forward to your help.

Thanks,

nada

I need help on maple code for solving both linear and non linear boudary condition for fractional order partial differential equation 

I cannot solve the equation. The problem is:

we have the integrals (1) and variable (2)
(1) F := (a1, b1) -> int(1/sqrt(1 + (-1)*b1^2*sin(teta)*sin(teta)), teta = 0 .. a1)

(2) Phi(Pi/2, teta) = 2*(F((Pi/2 - teta_l)/2, sqrt(2/(1 - sin(teta_l)))) - F1(Pi/4, sqrt(2/(1 - sin(teta_L)))))/sqrt(sin(teta_l) - 1)

After the solution for variable (2) I received: 

(-InverseJacobiAM(-Pi/4 + teta_l/2, 1/abs(cos(Pi/4 + teta_l/2))) - InverseJacobiAM(Pi/4, 1/abs(cos(Pi/4 + teta_l/2))))^2/(2*(sin(teta_l) - 1))

Next, I have the equation and (by the followed paper) should solve the equation respect to teta_l

M*B*(L/C)^2/G = 1/8*Phi(Pi/2, teta_l)^2

But I received just empty solution. The reference paper 10.1016/j.jmps.2020.104045

Can somebody recommend the way to solve the problem? 

I need to declare a whole set of variables as local. The variable names are generates algorithmically using assign. Like so:

seq(seq(assign(cat(S,i,j)=Vector(datatype=float)),i=1..9),j=1..9);

Stand-alone, this works and creates all these Vectors for later use. But this:

local seq(seq(assign(cat(S,i,j)=Vector(datatype=float)),i=1..9),j=1..9);

does not work; I get an "error; '(' unexpected".

I really do not want to type all these by hand... on the other hand, if I do not declare these as local I get 99 warnings about implicit local declaration; not nice.

Is there a way to do this?

Thanks,

M.D.

PS: I do not upload as the one line really is all that is needed. At the lowest level one does not get the implicit-declaration warning, but with "local" it still fails.

My forced spring mass system is 4x"+4x'+3x=sin(wt). I calculated my w=w* value that maximizes the amplitude (0.5) and my initial conditions are x(0)=x'(0)=0. I need to graph x(t) when w= w* and when w=w*/2. How am I supposed to input this information into maple to create a graph? 

Hi all,
i'm working with the confluent Heun function (Maple 2019).
Since for the case of an integer coefficient delta or gamma there are two integer Frobenius roots at the regular singularities 0 or 1, there is a logarithmic term in the Frobenius solution at these singularities. So, my question is the following:
When moving around this singularity in the complex plane, the value of the logarithmic term might depend on the choice of the complex logarithm's branch cuts. So, does anybody know just about how HeunC is implemented? Is there sth like a power series solution, which value would in my oppinion depend on this choice of a branch cut?
Or is there another implementation that preserves us from this ambiguity in the case of logarithmic singularities (i.e. integer coefficients in the confluent Heun equation)?

Many thanks,

This worksheet creates geodesics in the Poincare disk by transformation of a series of circles of diminishing radii in the complex plane.

The intersections of the geodesics are meant to create the first few pentagonal uniform tilings in the Poincare disk.

I do not know the mathematically correct way to create such a display, so the radii of the circles are only a trial and error approximation.

What Maple code will provide the radii of the complex circles which produce an accurate uniform pentagonal tiling?

Is there a better overall strategy for producing uniform tilings of the Poincare disk? 

HyperbolicTiling.mw

When I use Solve for a PDE with the option singsol=all, is Maple guaranteeing that I am getting all the solutions, and in partidcular , is it returning the *general* solution(s)? 

One of our users asks how they can find the Re ( sqrt(a+I*b)) where a, b are real.

They had tried entering the latter as "assume", without any luck. 

We told them that it may not be very intuitive, but such expressions can be evaluated by wrapping into evalc which implicitly assumes that free parameters are real-valued:

evalc(Re(sqrt(a+I*b)));

How is the matrix of the affinity of base the plan of equation x+2*y-z=1, of direction u <1,0,-1>and of ratio 2 determined? Thank you.

Hi,

I am trying to learn how to apply initial conditions to pdes with maple.  I have figured out how to do it with odes, but when assigning initial values to derivatives, I get weird results.  I have attached my Maple file, with the error, and a link to the document I am using as motivation for my analysis.

Test_1D_Wave_Equation.mw

https://personal.math.ubc.ca/~ward/teaching/m316/lecture21.pdf

I used to have this kind of code without problem:

myModule := module()
    option package;
    export myFunc;
    # local i;
    myFunc := proc()
        [seq(i, i in 1..10)]
    end proc;
end module;

But after upgrading to the latest version of Maple 2021, I get a warning

Warning, (in myModule:-myFunc) `i` is implicitly declared local |myModule.mpl:5|

I have to uncomment the local i declaration for the warning to go away. Has the behavior of seq changed in Maple 2021?

Maple returns to me an algebraic expression that involves many RootOf expressions and I have found it hard to get all solutions behind this expression (by using "allvalues") - this keeps on running without terminating. Is there a way to get the number of solutions without asking Maple to return all solutions explicitaly?

Dear Useres!

Hope everyone is fine here! I want to compare the coeficient of exp(k*eta[3]+m*eta[1]+n*eta[2]) for k=0,1,2,3,...,N,n=0,1,2,3,...,N and m=0,1,2,3,...,N for N=10 in the following attached file. But I got some error, please have a look and try to fix it as early as possible. Please take care and thanks

Compare_coeff.mw

In mathematica, CommunityGraphPlot attempts to draw the vertices grouped into communities. 

g = Graph[{1 \[UndirectedEdge] 2, 2 \[UndirectedEdge] 3, 
   3 \[UndirectedEdge] 4, 1 \[UndirectedEdge] 4, 
   1 \[UndirectedEdge] 5, 5 \[UndirectedEdge] 6, 
   5 \[UndirectedEdge] 7, 7 \[UndirectedEdge] 8, 
   8 \[UndirectedEdge] 9, 7 \[UndirectedEdge] 9}, 
  VertexLabels -> "Name"];
ged = {{6, 7, 8, 9}, {5}, {1, 2, 3, 4}};# Gallai-Edmonds decomposition
CommunityGraphPlot[
 HighlightGraph[g, FindIndependentEdgeSet[g], 
  GraphHighlightStyle -> "Thick"], 
 Thread[Labeled[ged, {"D(g)", "A(g)", "C(g)"}]], PlotTheme -> "Web"]

This function is very useful, for example, if I get a partition of vertices, such as the gallai-Edmonds decomposition below, I use  CommunityGraphPlot to easily see the overall layout of the graph. I don't know if Maple has a corresponding function.

PS: The Gallai-Edmonds decomposition of a graph g is the partition {D(g),A(g),C(g)} of its vertices, where D(g) consists of every vertex v for which there exists a maximum matching of g that misses v, A(g) consists of every vertex v that is not in D(g) but neighbors some vertex in D(g) and C(g) consists of all remaining vertices.
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