hi, I wonder why this output is empty because I tried to get solution below partial equation:

restart;
with(PDEtools);
pe := diff(u(t, x, y), t) = u(t, x, y) - diff(u(t, x, y), x $ 2) - diff(u(t, x, y), y $ 2) + (1 + u(t, x, y)*I)*abs(u(t, x, y))*u(t,x,y)^2;                                  
inc := u(0, x, y) = cos(Pi*x/50) - cos(Pi*x/150)*I;
sys := [pe, inc];
   

pdsolve(sys);
 

end after this pdsolve(sys); Maple doesn't show anything

thanks in advance

when I define piecwise function as

f := x -> piecewise(0 <= t, 1, t < 0, t - 1)

and I define his antiderivative

F := x -> int(f(t), t = 1 .. x)

F(x)

Maple gives

x - 1

which is obviously wrong (but I guess it's ok only for x=>0)

what to do to be correct?

plot3d(abs(Zeta(x + y*I)), x = -4 .. 5, y = -10 .. 40, view = [-4 .. 5, -10 .. 40, 0 .. 4])

Hi, is it possible to stretch y axis to get more satisfyng view of this graph? (without using scaling cosntrained)

x0 := x - Pi/4;
y0 := y - Pi/4;
z0 := z - Pi/4;
f := (x, y, z) -> 10*sin(x0)*sin(y0)*sin(z0) + 10*sin(x0)*cos(y0)*cos(z0) + 10*cos(x0)*sin(y0)*cos(z0) + 10*cos(x0)*cos(y0)*sin(z0) - 7/10*cos(4*x) - 7/10*cos(4*y) - 7/10*cos(4*z);
implicitplot3d(evalc(f(x, y, z) = 9), x = -4.5 .. 4.5, y = -4.5 .. 4.5, z = -4.5 .. 4.5, grid = [60, 60, 60], style = patchnogrid);

Hi, do you know how can I restrict this plot using another implicitplot3d let's say sphere given by x^2+y^2+z^2<=4.5?

f := z -> 1 + z/(1 + z^2/(1 + z^3/(1 + z^4/(1 + z^5/(1 + z^6/(1 + z^7))))))

Hi,do you know how to write a loop that would create such a continued fraction?