Maple always starts a new document with a 2D input style and Times New Roman font. How to change the boot style? (default).
Oliveira

pde := (diff(u(r, theta), r) + r * diff(u(r, theta), r, r) + diff(u(r, theta), theta, theta) / r ) / r:
iv := u( 1, theta) = 0, u( 3, theta) = theta, u( r, 0) = 10, u( r, Pi/2) = 0:
           Maple 2019 returns a symbolic solution for PDE:
pdsolve([pde, iv], u(r, theta));
   But for the numeric option, it returns a message saying that Maple is unable to handle elliptical PDEs.
pdsolve(pde, {iv}, numeric, time = t, range = 1 .. 3);

Error, (in pdsolve/numeric) unable to handle elliptic PDEs
I found it strange.

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