Hi,

I want to convert BesselJ(n,x) to the spherical version of it.

Is there a defined command in Maple that does this??

For example: 

sqrt(Pi)*sqrt(2)*BesselJ(1/2, x)/(2*sqrt(x))

is equivallent to

sin(x)/x

Indeed, the latter is the spherical version of the former one.

However, I can define a function that does it, see:

SBesselJ := proc (n,x) options operator, arrow, function_assign; expand(simplify(sqrt(Pi/(2*x))*BesselJ(n+1/2, x),'assume = positive')) end proc;

but is there a command that converts some terms to our defined function?? 

Thanks in advance.

Dear all,

I do not understand the output of the "Dual" command in the Logic package.

According to the help:

"The Dual command returns the dual of the Boolean expression b, that is, the expression generated by replacing &and with &or, &or with &and, leaving &not fixed, and extending to the remaining Boolean operators by their formulas in terms of &and, &or, and &not."

Applying Dual to "a &implies b" gives:
  `Logic:-&implies`(`&not`(a), `&not`(b))

But "a &implies b" is equivalent to "&not(a) &or b" and its Dual would be "&not(a) &and b", which is not equivalent to the result Maple returns.

Best regards,
 Anthei

Ha := 5; Gr := 2; Pr := 8; b := 4; lambda := 3;
PDE := {diff(theta(x, t), t)-(diff(theta(x, t), x, x))/Pr = 0, diff(u(x, t), t)-(diff(u(x, t), x, x))+Ha*u(x, t)-Gr*theta(x, t) = 0};
IBC := {theta(0, t) = 1+b(1-cos(lambda*t)), theta(1, t) = 1, theta(x, 0) = 0, u(0, t) = 1-cos(t), u(1, t) = 1, u(x, 0) = 0};
      {theta(0, t) = 5, theta(1, t) = 1, theta(x, 0) = 0, 

        u(0, t) = 1 - cos(t), u(1, t) = 1, u(x, 0) = 0}
pds := pdsolve(PDE, IBC, numeric);
                          module()...end module

how we can expand module()...end module and see solutions of the problem.
 

How to solve the following system of ode analytically in maple?

diff(s(t), t) = gamma*s(t) + eta*s(t) + sigma*m(t)*s(t) - kappa*s(t) - phi*s(t), diff(g(t), t) = -alpha*g(t)*m(t) + mu*g(t) + delta*s(t)*g(t), diff(m(t), t) = beta*s(t) - alpha_1*g(t)*m(t)

Hi there.

There is some floating bug in Thread-Seq.

Maple is crashing sometimes (not always, 50/50) after running the script below:

thread-seq_error.mw

What's going on?

Hi,

I am a newbie in Maple. I have the following code

with(LinearAlgebra):
w := (2*Pi)/14
v := Vector([1, sin(w*t), cos(w*t)])
simplify(sum(v . (Transpose(v)), t = k .. k + 13))

Even with some less advanced CAS I get that the result is a diagonal matrix with constant elements. However, I failed to properly tune the simplify command to get such a result. What I am doing wrong?

I have two questions:

1) How can I select only parts of an equation in a Maple Workbook? E.g. I have

4*x^2*(1 + x)^2*(x^2 + 6*x + 1)

and I want to select the text between the first "2" and the "6", but Maple always extends the selection to include the complete bracket. This is very annoying :)

2) How can I copy text from a maplesoft page into a workbook. E.g. I'm looking at

https://www.maplesoft.com/support/help/maple/view.aspx?path=updates/Maple2021/ODEsandPDEs

and I would like to select and copy some of the shown examples so that I can use them.

I believe I have found a bug or unintended behaviour:

The following second-order DE:

mplinput := ((x^4 + 4*x^3 + 10*x^2 + 4*x + 1)*diff(y(x), [x $ 0]))/(4*x^2*(1 + x)^2*(x^2 + 6*x + 1)) + 2*(x^2 + 5*x + 2)*diff(y(x), [x $ 1])/((1 + x)*(x^2 + 6*x + 1)) + diff(y(x), [x $ 2])=0:

can be solved by

with(DEtools):
hypergeometricsols(mplinput);

in terms of hypergeom functions. However,

dsolve(mplinput, [hypergeometricsols]);

does not find a solution, although it is supposed to use the same algorithm. One can trace this back to the sub-algorithm 'DEtools/2F1: --- find_2f1 ---' which is apparantly used by hypergeometricsols, but not by dsolve.

Another thing is that dsolve(mplinput, [hypergeometricsols]) in fact works in Maple2020, but does not in Maple2021 and Maple2022.
 

Hi, 

I installed syrup within Maple 2022 according to the procedure described in syrup's README file. The installation seems to run normally. After that I restarted Maple. When I now enter

with(Syrup);

it shows

[Draw, Library, Print, Solve, ToModelica, ToSpice, Version]

instead of 

[deindex, makecheckttable, printdeck, reindex, syrup]

as described in the application center: https://www.maplesoft.com/applications/Preview.aspx?id=4680

Also the example which is decribed there doesn't work:

syrup(divider, dc, 'curr');

delivers no result.

I'm working on Windows 10 64 bit.

Could it be that syrup is not yet prepared for Maple 2022, as it seems not to be updated for a long time? Or is the description in the application center not up to date?

Many thanks for your help!

Best regards,

Michael

Hi,all

I am new in Maple,when I execute the "InversePlot" command ,all functions were correct except for exp(x), error occurs as follows, can anyone tell me what mistake I took?

Tks in advance!

restart;
with(Student[Calculus1]);

InversePlot(exp(x), -1 .. 1);
Error, (in Student:-Calculus1:-InversePlot) module does not export `IsTrigProc`
 

Tks for all you guys. 

I have uninstall Maple and deleted the installed directory ,clear the register,reinstall Maple 2022, now all works well.

I think the problem is I installed Maple 2022 in the old directory of 2021for keeping my configuration,this caused much unexpected problem

I want to create a variable that is made up of a letter and an arrow on top. How to do that?

Also, how can I create a variable that is bold? I tried to type it as bold and then assign. But when I hit return it returns a normal symbol.

How to distinguish between a scalar variable and a vector variable in Maple?

Hi,

I want to solve a differential equation and plot the particle densities versus the distance.

How can I do this in Maple?

DE.mw

Sincerely

Suppose I want to calculate gcd(g(x),f(x))=a(x)f(x)+b(x)g(x) for two polynomial, i.e finding the RHS representation of the gcd, then how to implement this in maple?

I know of the command GCD(f(x),g(x)) but how to find the RHS representation?

Thanks!

Many formulas use a capital D to define parameters. A popular example is the second moment of area "I" of a tube. In Maple we get

Both I and D are protected symbols in Maple and are therefore printed in roman. With the "local" command, I and D can be used as unprotected symbols. However, only the unprotected "I" is printed in italic (like other symbols or names do). D is still printed in roman, which spoils Maple's excellent printout (a bit).

I hope this inconsistency can be improved one day. For the time being, I am looking for better alternatives than my workaround with a fat white space in the attachment. Are there better workarounds?

Italic_I_and_D.mw