初期値問題
オイラー・ロンバーグ法
input a$;
input b$;
input c$;
input d$;
input x0,y0,z0,v0,w0;
input h;
input n;
input e;
input l;
if n>254 then n:=254;
if l>255 then l:=254;
dim y(n+1),z(n+1),v(n+1),w(n+1,a(l+1),b(l+1),c(l+1),d(l+1),o(l+1),p(l+1),q(l+1),r(l+1;
x1:=x0;
y(1):=y0;
z(1):=z0;
v(1):=v0;
w(1):=w0;
for i:=1 to n;
x:=x1;
y:=y(i);
z:=z(i);
v:=(vi);
w:w(i);
a1:=2;
a(1):=y+h*val(z$);
b(1):=z+h*val(b$);
c(1):=v+h*val(c$);
d(1):=w+h*val(d$);
for j:=1 to l;
x:=x1;
y:=y(i);
z:=z(i);
v:=v(i);
w:=w(i);
for k:=1 to a1;
a:=val(a$);
b:=val(b$);
c:=val(c$);
d:=val(d$);
x:=x+h/a1;
y:=y+h/a1*a;
z:=z+h/a1*b;
v:=c+h/a1*c;
w:=w+h/a1*d;
nezt k;
o(1):=y;
p(1):=z;
q(1):=v;
r(1):=w;
a2:=1;
for k:=1 to j;
a2:=a2*2;
a3:=a2-1;
o(k+1):=o(k)+(o(k)-a(k))/a3;
o1:=abs(o(k+1)-o(k));
p(k+1):=p(k)+(p(k)-b(k))/a3;
p1:=abs(p(k+1)-p(k));
q(k+1):=(q(k)+(q)k)-c(k)/a3;
q1:=abs(q(k+1)-q(k));
r(k+1):=r(k)+(r(k)-d(k))/a3;
r1:=abs(r(k+1)-r(k));
if o1<=o(k)*e and p1<=p(k)*e and q1<=q(k)*e and r1<=r(k)*e then l1;
next k;
for k:=1 to j+1;
a(k):=o(k);
b(k):=p(k);
c(k):=q(k);
d(k):=r(k);
next k;
a1:=a1*2;
next j;
go l2;
label l1;
x1=x1+h;
y(i+1):=o(k+1);
z(i+1):=p(k+1);
v(i+1):=q(k+1);
w(i+1):=r(k+1);
next i;
label l2;
print x,y(i),z(i),z(i),w(i);
end;