Differanse operatorer

Forover differanse <jsm>\Delta\, u(x)=u(x+h)-u(x)</jsm>
Bakover differanse <jsm>\nabla\, u(x)=u(x)-u(x-h)</jsm>
Sentral differanse <jsm>\delta\, u(x)=u(x+\frac{h}{2})-u(x-\frac{h}{2})</jsm>
Middelverdi <jsm>\mu\, u(x)=\frac{1}{2}[u(x+\frac{h}{2})+u(x-\frac{h}{2}) ]</jsm>
Skift <jsm>E \,u(x)=u(x+h)</jsm>
Enhet operator <jsm>\mathbb{1}\, u(x)=u(x)</jsm>
2012-01-09, Trond Kvamsdal