## How to kill a Maple session...

 > restart;
 > kernelopts(version);

 > convert([1,2,3], Vector[row]);

 > convert([1,2,3], Vector[col]);

## Trouble with pdsolve...

This worksheet shows an unexpected behavior of pdsolve().  It solves the heat equation on the interval (−1,1) but fails on the interval (0,1).  I see no technical reason for this happening — it's probably due to a little bug lurking somewhere.

 > restart;
 > kernelopts(version);

 > Physics:-Version();

Solve the heat equation on the interval  and

boundary conditions

 > pde := diff(u(x,t),t) = diff(u(x,t),x,x);

 > bc := u(-1,t)=0, u(1,t)=0;

 > ic := u(x,0) = cos(Pi/2*x);

 > pdsol := expand(pdsolve({pde,bc,ic}));

That's good.  Apply pdetest to verify it:

 > pdetest(pdsol, [pde,bc,ic]);

Now, solve the same problem on the interval  and

boundary condition  and .  It should be

evident that the solution remains the same as the one calculated

above, due to symmetry, and here is the verification:

 > bc_new := D[1](u)(0,t)=0, u(1,t)=0;

 > pdetest(pdsol, [pde,bc_new,ic]);

But for some reason Maple's pdsolve fails to solve the PDE.  Actually

its response is somewhat erratic -- sometimes it returns nothing at all,

and sometimes it exits with an error message.

 > pdsolve({pde,bc_new,ic});

## Multi-precision linear programming...

I need to solve general linear programming problem with multi-precision support. What are my options with Maple 2020?

## Sawtooth Animation...

Hello

This is a sawtooth GIF from the wikipage Sawtooth wave

I want to recreate this animation in Maple. Could someone help me out with the formula to create this

## This is not a list...

What have I done!

Whatever I have created - Maple doesn't think it is a list.

The question is - what is it then?

proclist.mw

## How to numericaly solve a system of differential e...

I'm trying to obtain the dynamical response of a simply-supported beam with a cantilever extension, coupled to a spring-mass system. In mathematical terms, this system is ruled by three PDEs (relative to each bare part of the main structure) and one ODE (relative to the spring-mass system). I think my mathemical model is finely formulated, but Maple keeps telling me this:

`Error, (in pdsolve/numeric/process_IBCs) improper op or subscript selector`

I believe it is because my PDEs depend on "x" and "t", while the ODE depends solely on "t". I have tried to transform my ODE into a "PDE", making it also dependent of "x", but without imposing any boundary conditions relative to "x". However, after this Maple points a new error message:

`Error, (in pdsolve/numeric) initial/boundary conditions must be defined at one or two points for each independent variable`

Could someone help me finding a solution? My algorythm in shown in the attached file below.

Worksheet.mw

## Difficulties in integrating and plotting...

I'm trying to plot this integral but without success. Could someone help me?  I tried it the following way.

Thanks in advance for any help!

integral_test.mw

## How do I draw a petersen graph?...

Hello everyone, we are doing some excercises on graphs. The commands PetersenGraph and GeneralisedPetersenGraph only draw an indirected one, and i was wondering, is there a way to draw a directed Petersen graph?

## Why does the exception indexing function prevent m...

Here's a very simple example, working as intended:

Now, if I try to use the exception indexing function:

We can notice that b[1] isn't using exception anymore (as if the fourth input overwrote the second one) and that b[1][2] isn't linked to the value "two". However, if I define the tables first, I get the expected result:

Why does the exception indexing function prevent me from getting an existing table entry in the second case?

## how to draw ellipsoid from implicit plot of ellip...

Hi,

how to generate a graph of ellipsoid from ellipse equation ( revolution x axis or y axis) ?

Thanks

QEllipsoide.mw

## Incorrect definite integration of hyperbolic funct...

Hi Guys,

I am trying to intgrate a function involving hyperbolic functions in a range of 0 to 1 and it is giving me very large value of 10^94. However, on doing integration terms terms i can see that some large terms involving 10^191 cancel out with each other and I can have a fnite value of this integration. It would be really helpful if someone can help me out why it is happening with int function and how can I solve this case involving hyperbolic function. For reference maple file is attached. Thanks in advance and much appreciated.

With Regards

Sunit

question.mw

## Length of lines in a 2d shape not displaying corre...

I've drawn shape with the Graph function and all the lines are drawn as the same length even though the shape is weighted and when I do the WeightMatrix function I get the right weights.  What do I need to do to have the lines drawn to the correct length?

## How do I add to the list in my procedure in Maple?...

THE ISSUE: It's returning a list of [1] when it should be returning [1,1,1,7]

##Find remainder##
rm := proc(a, b) local n; n := 0; while 0 <= b - n*a do n := n + 1; end do; b - (n - 1)*a; end proc;
rm := proc (a, b) local n; n := 0; while 0 <= b-n*a do n := n+1

end do; b-(n-1)*a end proc

rm(8, 3657);
1

rm(16, 12345);
9

##FINDING THE WHOLE NUMBER PORTION ##
whole := proc(a, b) local r, i; r := 0; i := 0; if a < b then r := rm(a, b); i := (b - r)/a; else 0; end if; end proc;
whole := proc (a, b) local r, i; r := 0; i := 0; if a < b then

r := rm(a, b); i := (b-r)/a else 0 end if end proc

whole(8, 3657);
457

whole(16, 12345);
771

j = whole(8, 3657);
j = 457

k = rm(8, 3657);
k = 1

L := [];
L := []

L := [op(L), rm(8, 8657)];
L := [1]

j = whole(8, 457);
j = 57

##GETTING THE LIST OF DIGITS (BEFORE REVERSING)##
HELPER := proc(a, b, L) local j; j := whole(a, b); [op(L), rm(a, b)]; if 0 < j then HELPER(a, j, L); else ; end if; L; end proc;
HELPER := proc (a, b, L) local j; j := whole(a, b); [op(L),

rm(a, b)]; if 0 < j then HELPER(a, j, L) else  end if; L end

proc

CNS := proc(a, b) HELPER(a, b, L); end proc;
CNS := proc (a, b) HELPER(a, b, L) end proc

CNS(8, 3657);
[1]

HELPER(8, 3657, L);
[1]