/usr/share/doc/freefem-examples/heat.pde is in freefem-examples 3.5.8-5.1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | h0 := 1.0; h1 := 1.0;
border(2,0,1,4) begin x:= 10; y := h0 * t end;
border(2,0,1,4) begin x:= 10; y := h0 + h1 * t end;
border(4,0,1,4) begin x:= 0; y := h0 + h1 * (1-t) end;
border(4,0,1,4) begin x:= 0; y := h0 * (1-t) end;
border(1,0,10,40) begin x:= t; y := 0 end;
border(3,0,10,40) begin x:= 10 - t; y := h0 + h1 end;
border(0,0,10,40) begin x:= t; y := h0 end;
buildmesh(800);
t0 = 10; t1 = 100;
kappa =0.01 + one(y > h0);
plot(kappa);
solve(v){
onbdy(4) v=t0;
onbdy(2) v = t1;
onbdy(1) dnu(v)=0;
onbdy(3) dnu(v)=0;
pde(v) -laplace(v)*kappa+id(v) = 0;
};
plot(v);
|