## How to start working on geometric algebra...

Hello,

I have viewed on youtube the video "A Swift Introduction to Geometric Algebra" and i would like to start on the same subject with Maple but i don't even know to start !!

Do you have an idea how to start doing simple things like the "geometric product", operations on bivectors, trivectors....

Thanks

## Warning,Solving for expressions other than names o...

Please,Help the Maple code for find the values of F,F,F,........How to rectify this error?
 > >    (1)
 >   > ## HPM error with different do and end loop for same...

Dear maple user,

I have codes for Differential equations while applying one do and end loop i am able to plot the graph of G(x) while same problem with other way of applying do and end loop i am unable to plot. whats wrong with do and end loop. These are codes available in maple primes . while combining i am unable to plot .

any one resolve it.

restart:
with(DETools):
with(plots):
with(IntegrationTools):
de0 := {
(1-p)*(diff(f(x),x,x,x))+p*(diff(f(x),x,x,x)+(1/2)*f(x)*(diff(f(x),x,x))),
(1-p)*(diff(g(x),x\$2))/Pr+p*((diff(g(x),x\$2))/Pr+(1/2)*f(x)*(diff(g(x),x)))}:

ibvc0 := {f(0),(D(f))(0),(D(f))(5)-1,g(0)-1,g(5)}:
n:=2:

F := unapply( add(b[k](x)*p^k,k=0..n), x ):
G := unapply( add(c[k](x)*p^k,k=0..n), x ):

de := map( series, eval( de0, {f=F,g=G} ), p=0, n+1 ):

for k from 0 to n do

if k = 0 then
ibvc := expand( eval[recurse]( ibvc0, {f=F,g=G,p=0} ) ):
else
ibvc := { b[k](0), D(b[k])(0), (D@@2)(b[k])(0), c[k](0), D(c[k])(0) }:
end if:

sys := simplify( map( coeff, de, p, k ) ) union ibvc:
soln := dsolve( sys ):

b[k] := unapply( eval( b[k](x), soln ), x ):
c[k] := unapply( eval( c[k](x), soln ), x ):

end do:

'F(x)' = F(x)+O(p^(n+1)):
'G(x)' = G(x)+O(p^(n+1)):

Pr:=1:
plot(eval(G(x), p = 1), x = 0 .. 5, color = blue):
###### Same problem with other  way of do and and end loop unable to plot with G(x)
restart:
with(DETools):
with(plots):
with(IntegrationTools):
Pr:=1:
de1 := (1-p)*(diff(f(x), `\$`(x, 3)))+p*(diff(f(x), `\$`(x, 3))+(1/2)*f(x)*(diff(f(x), `\$`(x, 2))));
de2 := (1-p)*(diff(g(x), `\$`(x, 2)))/Pr+p*((diff(g(x), `\$`(x, 2)))/Pr+(1/2)*f(x)*(diff(g(x), x)));
ibvc := f(0), (D(f))(0), (D(f))(5)-1, g(0)-1, g(5); n := 2; F := unapply(add(b[k](x)*p^k, k = 0 .. n), x); G := unapply(add(c[k](x)*p^k, k = 0 .. n), x);
DE1 := series(eval(de1, f = F), p = 0, n+1);
DE2 := series(eval(de2, g = G), p = 0, n+1);
CO := map(coeffs, eval([ibvc], f = F), p); CT := map(coeffs, eval([ibvc], g = G), p);

for k from 0 to n do IBVC1 := select(has, C*T, c[k]); slv := dsolve({coeff(DE2, p, k), op(IBVC1)}); c[k] := unapply(rhs(slv), x) end do;
G(x) = G(x)+O(p^(n+1));
plot(eval(G(x), p = 1), x = 0 .. 5);

## How to rectify the "Error, invalid subscript selec...

Hi, Maple users

I hope you are doing well.
Here I solved one of the ode problems by dsolve.
But I am getting  "Error, invalid subscript selector" error.
Kindly do the needful to find a solution.
Thank you.

JVB.mw

## Why does the "D" operator behave different in the ...

I want to explore multivariable function approximations using truncated Taylor series.

Mathematically, for a function f(x,y) and using operator notation for the partial derivatives, where e.g. Dx2 f(x,y) denotes the second partial derivative of f wrt evaluated at (x,y), we can write the N'th order truncated Taylor series for f around (x0,y0) as I want to make a Maple-function for this expression, and try

P := (x,y,x0,y0,N) -> sum(1/factorial(n)*sum(binomial(n,k)*
D[1\$(n-k), 2\$k](f)(x0,y0)*(x-x0)^(n-k)*(y-y0)^k, k=0..n), n=0..N):

where f(x,y) is a previosly defined Maple-function.

My P function fails, and the reason why it fails is related to the "D" operator in the "sum".

Please take a look at the following code-snippet: Output (9) is as expected, but output (8) is not !!
I would expect output (8) to be equal to the sum of output (9), i.e. to be equal to (-1/2).

Please illuminate why I don't get the sum of the sequence (9) as my output (8).

## Unable to display plots...

Hellow,

I am unable to combine the graphs. I have a plot structure as

P1:=plots[odeplot](dsol, [x, F(x)], 0 .. 5, color = red);

P2:=plot(eval(F(x), p = 1), x = 0 .. 5, color = blue);

I want to combine two structure and display in same plot

display (P1,P2);

## How to convert a group into a PermutationGroup for...

I can get a group like this:

`g := SmallGroup(48, 8)` But I want to get the `PermutationGroup` form like `PermutationGroup({[[...]], [[...], [...]]})`. Can we change it into this form?

## Arial makes sign disappear in MathContainer...

Switching font to Arial apparently makes the sign disappear in MathContainers.

Vorzeichen.mw

## How do I do mathematical modelling of planetary mo...

If i want to do mathematical modelling for planetary motion, how can maple help me with it?

## How can i plot phase portrait? What is the problem...

I want to plot phase portrait but i get some errors. I didn't understand errors? Can anyone help me? zuhal_faz_portresi.mw

## Simplify; cleaning up array...

Dear power users, I probably have 2 dummy questions, which I show in the attached worksheet.

1. it looks to me that the equation can be further simplified than done by maple

2. is there a quick way in cleaning up the array by replacing the strings by something as NaN (not a number) so that I can use the array for numeric calculations?  (1)

why is the above not simplifying to  (2) How can I replace the strings in the matrix below by something like NaN (not a number) so I can use it for further numeric calculations?

 Error, invalid assignment  ## Is a bug of IsSubgroup?...

As we know, since the order about the element `Perm([[1, 2], [3, 4, 5]])` of S5 is 6. Then  the C6 is a subgroup of S5, but why `IsSubgroup(CyclicGroup(6), SymmetricGroup(5))` return `false`? Is it a bug?

## How to generate a polynomial corresponding to a so...

Of course, we know the A5 of 60 order is an unsolvable group, but as the wiki here, There are also some solvable groups in the same 60 order. Similarly, although `map(IsSolubleNumber, [60, 120, 168, 180])` will give `false`, there are some solvable groups in orders 60, 120, order 168, and order 180. But how to find these corresponding solvable polynomials by maple? I tried to generate them using random polynomials like this:

```with(GroupTheory);
do
do poly := randpoly(x, degree = rand(6 .. 8)()); until irreduc(poly);
G := GaloisGroup(poly, x);
until IsSoluble(G) and is(GroupOrder(G) in {60, 120, 168, 180});
poly;
galois(poly, x);```

But I didn't get any result even after one night..

## Maple Conference 2022: Call for Participation

by: Maple

We are holding another Maple Conference this year, and I am pleased to announce that we have just opened the Call for Participation!

This year’s conference will be held Nov. 2 – Nov. 3, 2022. It will be a free virtual event again this year, and it will be an excellent opportunity to meet other members of the Maple community and share your work.

We are inviting submissions of presentation proposals on a range of topics related to Maple, including Maple in education, algorithms and software, and applications. We also encourage submission of proposals related to Maple Learn. This year, we are not requiring recorded videos, and we hope to see more interaction between presenters and audience members in our live sessions.

You can find more information about the themes of the conference and how to submit a presentation proposal at the Call for Participation page. Proposals are due July 18, 2022.

Presenters will have the option to submit papers and articles to a special Maple Conference issue of the Maple Transactions journal after the conference.

Registration for attending the conference will open in June. We will also be featuring an art gallery again at the conference. Watch for further announcements in the coming weeks.

I sincerely hope that all of you here in the Maple Primes community will consider joining us for this event, whether as a presenter or attendee!

## bug in int/Dirac...

Hi folks

If you try this simple integral

simplify(int(P(q)*(Dirac(k-q)+ Heaviside(k-q)),q = 0..infinity)) assuming k>0;

it returns int(P(q), q = 0 .. k), completely ignoring the delta function. However, if you expand the integral first:

simplify(value(IntegrationTools[Expand](Int(P(q)*(Dirac(k-q)+ Heaviside(k-q)),q = 0..infinity)))) assuming k>0;