Oliveira

190 Reputation

3 Badges

9 years, 360 days

MaplePrimes Activity


These are questions asked by Oliveira

pde := diff(u(x, t), x $ 4) = diff(u(x, t), t $ 2);

iv:= subs(L = 100, {u(0, t) = 0, u(L, t) = 0, u(x, 0) = sin(x), D[2](u)(x, 0) = 2*x, D[1, 1](u)(0, t) = 0, D[1, 1](u)(L, t) = 0});

de := pdsolve(pde, iv, numeric):

sa1 := de:-value(output = listprocedure);

sa1:=[x=proc() ... end proc,t=proc() ... end proc,u(x,t)=proc() .. end proc]

    With the above procedure it works, but in the most compact form below it does not work.

pdsolve(pde, iv, numeric,output = listprocedure):

Error, (in pdsolve/numeric/par_hyp) invalid arguments for theta scheme: [output = listprocedure]
 

with(PDEtools);
pde := diff(c(x, t), x, x) - h*diff(c(x, t), x) = diff(c(x, t), t):

iv := c(0, t) = 0, c(a, t) = 0, c(x, 0) = c0:

de := pdsolve([pde, iv], c(x, t), build);

                         de := ( )

Does anyone know how to solve this PDE?
Thank you,

Oliveira

      

Is there any way to place a command to the right of an expression to perform a task? Because I only know the way that puts the command to the right.A simple example:

w1 := simplify(sin(x)2 + cos(x)2);

                       w1:=1

w2:=sin(x)2+cos(x)2:-simplify;
             Error, invalid module reference

I wonder if there is a way to put the commands, also to the right of the expressions, as above.

Thank you,

Oliveira
   

I would like to change the color and font type on the Maple-2019 inputs and outputs, so that these formatting would be applied every time I started a new document. I tried doing this through the Styles option on the Format menu, but I could not. Can anyone help? Thank you.


 

pde1 := k*(diff(u(x, t), x, x)) = diff(u(x, t), t)

k*(diff(diff(u(x, t), x), x)) = diff(u(x, t), t)

(1)

iv1 := u(0, t) = 0, u(L, t) = 0, u(x, 0) = 2;

u(0, t) = 0, u(L, t) = 0, u(x, 0) = 2

(2)

pdsolve([pde1, iv1], u(x, t))

u(x, t) = Sum(-4*(-1+(-1)^(_Z4*csgn(1/L)))*sin(Pi*_Z4*x/L)*exp(-Pi^2*_Z4^2*k*t/L^2)/(Pi*_Z4), _Z4 = 1 .. infinity)

(3)

subs(`~`[_Z4] = n, %)

u(x, t) = Sum(-4*(-1+(-1)^(_Z4*csgn(1/L)))*sin(Pi*_Z4*x/L)*exp(-Pi^2*_Z4^2*k*t/L^2)/(Pi*_Z4), _Z4 = 1 .. infinity)

(4)

``

 
"I would like to replace the symbol _Z4~ with the letter n. I tried with the subs command, but I could not. Can anyone help"?"" ""


 

Download evaluate_a_sum.mw

5 6 7 8 Page 7 of 8