Thomas Richard

Mr. Thomas Richard

1753 Reputation

12 Badges

9 years, 226 days
Maplesoft Europe GmbH
Technical professional in industry or government
Aachen, Germany

MaplePrimes Activity


These are answers submitted by Thomas Richard

Use the lhs command to obtain the left-hand side on an equation, and rhs for the right-hand side.

If you accept one extra statement:

with(LinearAlgebra[Modular]):
A := Mod(2,Matrix(3,6,(i,j)->if i<2 and j < 3 then 1  elif i = 2 and j > 2 and j <5 then 1 else 0 end if),float[8]);
A[-1,..] := 1;

Please see ?MVextract about the syntax.

Please open the Help menu, and you will find that info. If it doesn't work, please provide an example.

I will ask the documentation team to remove that link. Thanks for bringing it to our attention.

Besides the programmatic way described by Carl, you can change the default directory by clicking on its display in the status bar at the bottom of the Maple window.

You are right: the spec is too low, particularly the memory size. It may be possible to install Maple 2019 with 2GB RAM, but it will be slower than necessary, unless you do trivial calculations only. The CPU is also too weak.

System requirements are listed at https://www.maplesoft.com/products/system_requirements.aspx.

Combining plots (including implicit plots) is easily done by the display command of the plots package:

with(plots):
a:=1:
ip1:=implicitplot(x^3+y^3-3*a*x*y=0,x=-3..3,y=-3..3,gridrefine=3):
ip2:=implicitplot(x+y+a=0,x=-3..3,y=-3..3,color=blue,linestyle=dash):
display(ip1,ip2);

Also take a look at the algcurves package which has a plot_real_curve routine that is more useful for this type of implicit plots.

 

This BVP can be solved in a straightforward way, but you need Maple 14 or newer.

Side remark: you don't even need to load the PDEtools package for that. And simply writing its name won't load it anyways, the proper syntax is

with(PDEtools):

I'm uploading my worksheet, saved in Maple 14, and with all output so that you can see (but not reproduce) it in Maple 12.

 

 

restart

pde := diff(u(x, y), `$`(y, 4)) = 0

diff(diff(diff(diff(u(x, y), y), y), y), y) = 0

(1)

bc1 := u(x, 0) = 0; bc2 := (D[2, 2](u))(x, 0) = 0

u(x, 0) = 0

 

(D[2, 2](u))(x, 0) = 0

(2)

bc3 := (D[2](u))(x, 2) = (D[2, 2](u))(x, 2)+1

(D[2](u))(x, 2) = (D[2, 2](u))(x, 2)+1

(3)

sys := [pde, bc1, bc2, bc3]

infolevel[pdsolve] := 5

sol := pdsolve(sys)

* trying method "Fourier" for higher order PDEs

   -> trying a fourier transformation
* trying method "Laplace" for higher order PDEs
   -> trying a Laplace transformation
* trying method "Generic" for higher order PDEs
   -> trying a solution in terms of arbitrary constants and functions to be adjusted to the given initial conditions

   <- solution in terms of arbitrary constants and functions to be adjusted to the given initial conditions, successful
<- method "Generic" for higher order PDEs successful

 

u(x, y) = (1/6)*_C1*y^3+y

(4)

pdetest(sol, sys)

[0, 0, 0, 0]

(5)

NULL

``

 

PDEsolve-Maple14.mw

As always, the formatting is much nicer in the actual Maple session than its display in MaplePrimes.

Of course, for getting rid of the integration constant _C1 (and for plotting), you will need one more BC or IC.

If you're working in the field of BVPs for PDEs, we strongly recommend upgrading to the latest version. Lots of new functionality have been addedd in recent years by Edgardo S. Cheb-Terrab, please look up his contributions in this forum.

 

Please see https://www.maplesoft.com/support/index.aspx; the correct address is custservice@maplesoft.com. Briefly describe why you want to migrate a license, and include your 16-digit Purchase Code. Do not post any Purchase Code on MaplePrimes or elsewhere.

This depends on the operating system. Since chmod is a Unix command, you will find it on Linux and Mac OS X only, but not on Windows (unless you install Unix-like add-ons, which is not the case by default).

So I'm not aware of any genuine Maple features for that purpose.

However, you can query some basic permissions (read, write, execute) as well as modification time via appropriate FileTools package commands (preferrably the Status command).

Depending on what you want to achieve, it may be better to put the chmod call and the maple command into a common shell script. Just an idea...

combine(expand(expr));

Side remark: as you may have noticed in the replies, Maple expects Pi, not pi.

My recommendation for simplifying algebraic numbers or algebraic functions such as A and B is always the evala command. It is more generic than radnormal and expand (both of which have their benefits, too).

The error seems to be related to the floating-point number 6.05. If you replace it by a rational number like this:

Rf := 605/100;
Bc_s := k_s*eval(Gradient(T_s(r, theta), polar[r, theta])[1], r = Rf) = h_f*(T_s(Rf, theta) - T_f);

it goes away - but pdsolve finds no solution, as has been observed already.

For consistency reasons, you may also want to replace 5 by Ra and 6 by Rc in the other Bc settings.

Just end the line with a colon, as opposed to a semicolon. Displaying the table is (technically speaking) a side effect of the Tabulate command. Its main effect is returning a value, which is unwanted here. See the 2nd item of the Description section on the help page.

Just adding a hint to vv's answer: you can also let Maple do the transform:

VectorCalculus:-int(exp(-(sqrt(4*x^2+4*y^2+4*z^2)^3)), [x,y,z] = Sphere( <0,0,0>, 2, [r,phi,theta]), 'inert');
simplify(%); # optionally
value(%);

If you want to see the result and no intermediate steps, simply omit the 'inert' option.

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