Hi!

I've a problem with maple. I wonder to see the visualisation of the solutions of a system of partial equations :

with(PDEtools);

EDP := [diff(s(x, y, t), t) = -.45*i(x, y, t)*s(x, y, t), diff(i(x, y, t), t) = .45*i(x, y, t)*s(x, y, t)-.2*i(x, y, t)-.7*(diff(i(x, y, t), x)+diff(i(x, y, t), y))];

IBC := {s(0, y, t) = 1, s(x, y, 0) = f(x, y), i(x, y, 0) = g(x)};

f := proc (x) options operator, arrow; 1-g(x) end proc; g := proc (x) options operator, arrow; piecewise(x = 20, .2, 0) end proc

But when I write :