## How I find college students to create problem work...

I teach high school IB Math.

I want to find someone who can take problems I have created and enter them into Maple (problem and solution) so I can use those in my classroom.

I can keep up with the new stuff I create, but I have almost 20 years of accumulated material I'd like to move into Maple.

Does anyone know where I can find someone to enter the problem and solution so that it is proved out in Maple? Maybe an existing college student using Maple at their school for math, engineering, or education? I am willing to pay them, it is just locating them that is a problem.

Even if you know a site for maple contractor types, that would be helpful.

Thanks a ton!

Robert

## Finding a Derivative with Maple...

I have a function e^(-\lambda z \sqrt(x^2 + y^2)), is it possible to use Maple to find some sequence of derivatives wrt to x and y which could be applied to this function to get

(z/(1+2*sqrt(x^2 + y^2)*lambda))*e^(-\lambda z \sqrt(x^2 + y^2))

## Any maple built in function can find the possible ...

Any maple built-in function can find the possible numbers when modular a fixed number?

For example,

(x&^3+y) mod 124 = 123 mod 124

Find the possible values of x and y.

## Maple prints out in loop even though I tell it not...

for i from 1 to numelems(X) do
A := x:
B := C;
end;

maple will print all statements even though I use the colon to try to suppress the first line. This just seems wrong. If I suppress the entire loop I have to use prints, and if I have a lot of statements I have to do it for every one even if I just want to supress 1.

It seems maple is suppose to suppress but it isn't.

## How to stop maple from locking up and crashing and...

One problem I come across far to often is that if maple get's bogged down in a computation or I screwed something up I can't always stop it. Sometimes the red ! is greyed out and I have to kill the mserver. When I do this I get the error that I need to save but save doenst' work and I can't do anything because the the kernel was killed. Maple doesn't seem to be able to properly recover... even though it does it most of the time when I click on the red !.

Is there any way around this?

## Override function for new behavior...

I get tired of having to resize my plots constantly so I can get a nicer view.

setPlotSize:=proc(P,sz::[posint,posint])
op(0,P)(remove(type,[op(P)],'specfunc(ROOT)')[],
ROOT(BOUNDS_X(0),BOUNDS_Y(0),
BOUNDS_WIDTH(sz[1]),BOUNDS_HEIGHT(sz[2])));
end proc:

This let's one set the size(mine is usually 1200x500) but I have to stick it in every plot.

Is there a way to override the plot functions to automatically do this for every plot or create a simple short option to scale it to the window size or some specific size?

I could probably make a simple function like RPF()

that I can wrap every plot but I'd like to avoid that step and just apply it to all plots by default(since 99% of the time I have to scale them.

## Is "MultiSet" reliable?...

Something really weird is going on when I build a MultiSet in two different ways, using the "+" operation.  The two constructions give the same MultiSet (since U=V), but in some mysterious way they are not really equal (since X=Y is false).  Does anyone know how to avoid this?  Should the "+" operator be avoided altogether?

There is more:  I tried saving the values of X and Y using the command:  save X, Y, "anomaly.m"

I got the error message:  "Error, could not open anomaly.m for reading".

Thanks!

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## change variable in equation...

Hi everyone:

How can I re-write the EQ with transformation       s=1+2*((tau-t)/T0)    ?

EQ:=int(f1(t-tau)*(Sum(y[k]*F[k](tau), k = 0 .. M)), tau = t-T0 .. t)

tnx...

## How can I have a pretty display of a piecewise exp...

Hi,

How can I force the command InsertContent(Worksheet(Group(Input( T )))) to display the variable eq as it appears in label (2) ?

(a screen capture of the output of InsertContent(Worksheet(Group(Input( T )))) is given after the Maple code)

 > restart:
 > interface(version)
 (1)
 > with(DocumentTools):
 > with(DocumentTools[Layout]):
 > eq := piecewise(t < 1, sin(t), cos(t)); C := Cell( Textfield(style=TwoDimOutput,Equation(eq)) ): T := Table(Column(), widthmode=percentage, width=40, Row(C)): InsertContent(Worksheet(Group(Input( T )))):
 (2)
 >

## GKLS - Optimization test functions generator...

Hi!

There is a (relatively) known software code (written in C), called ." GKLS-generator" or "GKLS" to generate, according to certain user paramenters, optimization test functions. The code is available for free at the web

http://wwwinfo.deis.unical.it/%7Eyaro/GKLS.html

I would like to write this code in Maple. In the attached zip there is a PDF explaining how to build these functions. For now, I tried the follwoing Maple code GKLS_v4.mw

I think I'm doing something wrong, since the drawing generated by the attached Maple does not look much like the PDF in the attached zip (Fig. 1 of page 8).

Please, Can you help me with this?

## Maple not simplifies equation completly...

Hello

I have problem with Maple that is not simplifying equation completly:

My simplified equation:

Its sum of  for example 20 elements and only n is increasing so why maple will not move a,b,c,d ahead parenthesis ?

## Collocating a vector...

Hi User!

Hope you would be fine with everything. I have a vector "POL" of M dimension obatined for the following expression

restart; with(LinearAlgebra); nu := 1; M := 3;
for k while k <= M do
Poly[k] := simplify(sum(x^i*GAMMA(nu+1)/(factorial(i)*GAMMA(2*nu)), i = 0 .. k-1))
end do;
POL := <,>(seq(Poly[k], k = 1 .. M))

and I want to construct a matrix of M by M by collocating it on the points x=i/(M-1) for i=0,1,2,...,M-1 like the following way,

For M=3 I need

Matrix(3, 3, {(1, 1) = Poly[1](0), (1, 2) = Poly[1](1/2), (1, 3) = Poly[1](1), (2, 1) = Poly[2](0), (2, 2) = Poly[2](1/2), (2, 3) = Poly[2](1), (3, 1) = Poly[3](0), (3, 2) = Poly[3](1/2), (3, 3) = Poly[3](1)});

For M=4 I need

Matrix(4, 4, {(1, 1) = Poly[1](0), (1, 2) = Poly[1](1/3), (1, 3) = Poly[1](2/3), (1, 4) = Poly[1](1), (2, 1) = Poly[2](0), (2, 2) = Poly[2](1/3), (2, 3) = Poly[2](2/3), (2, 4) = Poly[2](1), (3, 1) = Poly[3](0), (3, 2) = Poly[3](1/3), (3, 3) = Poly[3](2/3), (3, 4) = Poly[3](1), (4, 1) = Poly[4](0), (4, 2) = Poly[4](1/3), (4, 3) = Poly[4](2/3), (4, 4) = Poly[4](1)})

and general form is like this

[[[Poly[1](0/(M-1)),Poly[1](1/(M-1)),Poly[1]((2)/(M-2)),...,Poly[1]((M-1)/(M-1))],[Poly[2](0/(M-1)),Poly[2]((1)/(M-1)),Poly[2]((2)/(M-1)),...,Poly[2]((M-1)/(M-1))],[Poly[3]((0)/(M-1)),Poly[3]((1)/(M-1)),Poly[3]((2)/(M-1)),...,Poly[3]((M-1)/(M-1))],[...,...,...,...,...],[Poly[M]((0)/(M-1)),Poly[M]((1)/(M-1)),Poly[M]((2)/(M-1)),...,Poly[M]((M-1)/(M-1))]]];

Another problem is I want to define a vector of M dimension using a function f(x)=sin(x) and two points a=1, b=2 like the following way,

Vec:=[[[a],[f((1)/(M-1))],[f((2)/(M-1))],[f((3)/(M-1))],[...],[f((M-1)/(M-1))],[b]]]
Special request @acer @acer @Carl Love @Kitonum @Preben Alsholm

## Simplification of an expression...

Dear Users!

Hope you would be fine with everything. I want the simpliest for of the following expression in two step:

diff(U(X, Y, Z, tau), tau)+U(X, Y, Z, tau)*(diff(U(X, Y, Z, tau), X))+V(X, Y, Z, tau)*(diff(U(X, Y, Z, tau), Y))+W(X, Y, Z, tau)*(diff(U(X, Y, Z, tau), Z))+u[delta]*lambda[1]*(diff(U(X, Y, Z, tau), tau, tau))/L[delta]+u[delta]*lambda[1]*(diff(U(X, Y, Z, tau), tau))*(diff(U(X, Y, Z, tau), X))/L[delta]+u[delta]*lambda[1]*U(X, Y, Z, tau)*(diff(U(X, Y, Z, tau), tau, X))/L[delta]+u[delta]*lambda[1]*(diff(V(X, Y, Z, tau), tau))*(diff(U(X, Y, Z, tau), Y))/L[delta]+u[delta]*lambda[1]*V(X, Y, Z, tau)*(diff(U(X, Y, Z, tau), tau, Y))/L[delta]+u[delta]*lambda[1]*(diff(W(X, Y, Z, tau), tau))*(diff(U(X, Y, Z, tau), Z))/L[delta]+u[delta]*lambda[1]*W(X, Y, Z, tau)*(diff(U(X, Y, Z, tau), tau, Z))/L[delta];
Step 1:
diff(U(X, Y, Z, tau), tau)+U(X, Y, Z, tau)*(diff(U(X, Y, Z, tau), X))+V(X, Y, Z, tau)*(diff(U(X, Y, Z, tau), Y))+W(X, Y, Z, tau)*(diff(U(X, Y, Z, tau), Z))+u[delta]*lambda[1]*(diff(diff(U(X, Y, Z, tau), tau)+U(X, Y, Z, tau)*(diff(U(X, Y, Z, tau), X))+V(X, Y, Z, tau)*(diff(U(X, Y, Z, tau), Y))+W(X, Y, Z, tau)*(diff(U(X, Y, Z, tau), Z)), tau))/L[delta];
Step 2: (final form I need)
(1+(u[delta] lambda[1])/(L[delta]) (&PartialD;)/(&PartialD;tau)) ((&PartialD;)/(&PartialD;tau) U(X,Y,Z,tau)+U(X,Y,Z,tau) ((&PartialD;)/(&PartialD;X) U(X,Y,Z,tau))+V(X,Y,Z,tau) ((&PartialD;)/(&PartialD;Y) U(X,Y,Z,tau))+W(X,Y,Z,tau) ((&PartialD;)/(&PartialD;Z) U(X,Y,Z,tau)));
Special request:
@acer @Carl Love @Kitonum @Preben Alsholm

## Maple Inner product for Tensors ...

I'm fairly new to using Maple and am having a bit of a hard time calculating the following inner product. Firstly, I define the tensors (which to this end I'm not certain they are correctly defined),

with(Physics):

Setup(mathematicalnotation=true)

Setup(coordinatesystems=spherical):

ds2 := - dt^2 + a(t)^2 /( 1-k*r^2)*dr^2 + a(t)^2*r^2*dtheta^2 + a(t)^2*r^2*sin(theta)^2*dphi^2;
Setup(coordinates = spherical, metric = ds2);

e[mu, ~nu] = Matrix(4, {(1,1)= a(t)/sqrt(1-k*r^2), (2,2)=a(t)*r, (3,3)=a(t)*r*sin(theta), (4,4)=1}, fill=0); (15)
Define((15))
f[~mu, nu] = Matrix(4, {(1,1)=sqrt(1-k*r^2)/(a(t)), (2,2)= 1/(a(t)*r), (3,3)=1/(a(t)*r*sin(theta)), (4,4)=1}, fill=0); (28)

Define((28))


Thus, I defined two mixed tensors e[mu, ~nu] (one covariant and one contravariant index ) and f[~mu, nu] (one contravariant and one covariant index).

Then, I try to take the following inner product between the two mixed tensors and the Christoffel symbols of the second kind, namely,

e[nu, ~alpha].f[~sigma, beta].Christoffel [~nu, sigma, mu];

where I used the Physics['.'] command . However, when I try taking this inner product, it returns unevaluated.

Did I define the mixed tensors incorrectly? Does it matter how you define the indices when you're gonna take the inner product? Because taking the inner product of simply e[mu, ~nu].f[~mu, nu] also returns unevaluated. Also, I should mention that  e[mu, ~nu] and f[~mu, nu] are inverses of each other, is there any way to define one and get the other, since, simply changing the way in which the indices are raised and lowered doesn't take the reciprocal of the components.

## Maple gives solution to PDE which does not satisfy...

Do you agree this solution given by Maple is not correct?

restart;
pde := diff(u(x,t),t)+diff(u(x,t),x)=0;
bc  := D[1](u)(0,t)=0;
ic  := u(x,0)=exp(-x^2);
sol:=pdsolve([pde,ic,bc],u(x,t)) assuming x>0,t>0;
pdetest(sol,pde)
`

Result of pdetest should be zero.

I think the PDE itself is not well posed (I copied it from different forum to see what Maple does with it). But still the solution clearly does not satisfy the PDE itself for x not zero.

Maple 2019.2.1 with Physics version 573

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