PK 17 06 2011 (matlab)

RungeKutta tingkat tinggi..

function pd2=frungekutta(sf,sg,x0,y0,z0,h)


f=inline(sf);

g=inline(sg);

n=11;

x(1)=x0;

y(1)=y0;

z(1)=z0;

for i=1:n

fprintf('%3g !%8.5f !%8.5f !%8.5f\n',i-1,x(i),y(i),z(i))

k1=h*f(z(i));

l1=h*g(x(i),y(i),z(i));

k2=h*f(z(i)+l1);

l2=h*g((x(i)+h),(y(i)+k1),(z(i)+l1));

y(i+1)=y(i)+(k1+k2)/2;

z(i+1)=z(i)+(l1+l2)/2;

x(i+1)=x(i)+h;

end

pd2=z(n);
 
 
 
 
Euler PD2
 
function pd2=feuler(sf,sg,x0,y0,z0,h)


f=inline(sf);

g=inline(sg);

n=11;

x(1)=x0;

y(1)=y0;

z(1)=z0;

for i=1:n

fprintf('%3g %8.5f %8.5f %8.5f\n',i-1,x(i),y(i),z(i))

y(i+1)=y(i)+h*f(z(i));

z(i+1)=z(i)+h*g(x(i),y(i),z(i));

x(i+1)=x(i)+h;

end

pd2=z(n);