1 | This give Iterative equation if we use k to label time steps |
2 | c1 yk+1(x,y) = ( y"k"(x+h,y) + y"k"(x-h,y)+y"k"(x,y+h)+y"k"(x,y-h))/4 |
3 | - c2 y"k"(x,y) |
4 | where c1 + c2 = 1 |
5 | and the value of c1,c2 depend on K,h and dt. |
6 | as dt is arbitary, we can choose c1 |
7 | (and hence c2 = 1 - c1 ) to optimize convergence. |
8 | We use cryptic notaation "k" to repreprent various possible choices for evaluating time on right hand side. Simplest is "k" = k but choices are k, k+1 or linear combinations which can vary for different x values. |