Hi there.

It looks strange but simplify/symbolic cannot handle expression in file:

Only after expanding numerator and denominator by hand.

I think simplify/symbolic should be smarter.

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Hi there.

It looks strange but simplify/symbolic cannot handle expression in file:

Only after expanding numerator and denominator by hand.

I think simplify/symbolic should be smarter.

March 31 2021

3
1

The following example (from help, direct call, without **with**) does not work.

restart; (Q[`0`],Q[`1`],Q[`+`],Q[`-`],Q[`*`],Q[`/`],Q[`=`]) := (0,1,`+`,`-`,`*`,`/`,`=`): A := Matrix([[2,1,4,6],[3,2,1,7],[0,0,5,1],[0,0,3,8]]): LinearAlgebra:-Generic:-Determinant[Q](A, ':-method' = ':-BerkowitzAlgorithm');

*==> error, (in hasoption)*

We must use:

LinearAlgebra:-Generic:-Determinant[Q](A, method=LinearAlgebra:-Generic:-BerkowitzAlgorithm); # 37

which I suppose is not intended!

That's because the keyword name in the code appears as **'BerkowitzAlgorithm'** instead of **':-BerkowitzAlgorithm'**

(The problem occurs because there is an export **LinearAlgebra:-Generic:-BerkowitzAlgorithm**).

March 31 2021

3
7

Hi, everyone, here is my maple code

restart;

In := 5.75*10^(-12);

M := 1000;

E := 10^12;

V := 100;

m := 2300;

K := 10^9;

A := E*In;

B := M*V^2;

C := 2*M*V^2;

F := M + m;

G := K;

pde := A*diff(w(x, t), x $ 4) + B*diff(w(x, t), x $ 2) + C*diff(w(x, t), x, t) + F*diff(w(x, t), t $ 2) + G*w(x, t);

tmax := 0.05;

xmin := 0;

L := 1;

bc := w(0, t) = 0, w(L, t) = 0, D[1, 1](w)(0, t) = 0, D[1, 1](w)(L, t) = 0;

ic := w(x, 0) = 0

pdsA := pdsolve(pde, eval({bc, ic}, L = 1), numeric, spacestep = 0.01)

I keep getting error message: Error, (in pdsolve/numeric/par_hyp) Incorrect number of initial conditions, expected 2, got 1

but when i change the pde to:

pde := A*diff(w(x, t), x $ 4) + B*diff(w(x, t), x $ 2) + C*diff(w(x, t), x, t) + F*diff(w(x, t), t) + G*w(x, t);

it works, although that is not what i am aiming for at all.

how may i solve this? my goal is to find w(x,t)

March 30 2021

1
1

Finite Fields package seemed very useless for my purpose.

Is there a way to do some linear algebra computation (finding rank, solving linear systems, finding span of vectors) over a finite field (GF(2), GF(5), GF(3^5) etc) ?

Thank you in advance

March 30 2021

1
1

Dear all

I have the following proc I, I need a help so that the proc run without error.

I get Error, invalid =

Code_eigenvalues_eigenvectors.mw

Thank you for any help

March 30 2021

2
2

Determine the sert of point Z in complex plane isuch that l2z-il=Im(z+1-i)

March 30 2021

2
5

Lets say I wanna write a procedure DrawSpaceCurve3d.

DrawSpaceCurve3d:=proc(fnc::algebraic, vars:name,h::integer, xvalue::range=a{integer}...b..{integer})

plots:-spacecurve([vars, h, funk(vars, h)], ':-x' = 'xvalue')

end proc;

How I try to run this procedure, then I get the following error.

"Error, (in Plot:-SpaceCurve) parameter range in the form name=range is missing"

So my question is it possible to get Maple to accept that I write DrawSpaceCurve3D(x^2*y, 2, xvalue=[-5..5])

I know the y - curve is missing, but I would like to see if I can get Maple to accept this kind of input?

I am trying to solve three simultaneous PDE where the first two PDEs are 1D while the third is 2D. When using pdsolve with numeric option I am getting the following error

Error, (in pdsolve/numeric/process_PDEs) PDEs can only contain dependent variables with direct dependence on the independent variables of the problem, got {Tg(t, z, 0.6985e-1)}. Can someone please help me with this.

restart; T_well := 10. + 0.026*z; PDE_in := -0.493381*diff(Ti(t, z), z) + diff(Ti(t, z), t) = 0.000176303*(-Ti(t, z) + To(t, z)); PDE_out := 0.186546*diff(To(t, z), z) + diff(To(t, z), t) = 0.0397694*(Tg(t, z, 0.06985) - To(t, z)) + 0.0000666597*(Ti(t, z) - To(t, z)); PDE_g := 0.22828*10^7/3.5*diff(Tg(t, z, r), t) = diff(Tg(t, z, r), r)/r + diff(Tg(t, z, r), r, r) + diff(Tg(t, z, r), z, z); PDE := {PDE_g, PDE_in, PDE_out}; IC := {Tg(0, z, r) = T_well, Ti(0, z) = T_well, To(0, z) = T_well} BC := {3.5*D[2](Tg)(t, 2000, r) = -3/40, 3.5*D[2](Tg)(t, z, 0.06985) = 0.0397694*(Tg(t, z, 0.06985) - To(t, z)), Tg(t, 0, r) = 10, Tg(t, z, 50) = 10 + 0.026*z, To(t, 0) = 10, To(t, 2000) = Ti(t, 2000)} pdsolve(PDE, IC, BC, numeric)

March 29 2021

1
3