Partial Differential Equation Toolbox |

poiindex

Indices of points in canonical ordering for rectangular grid

Syntax

-     [n1,n2,h1,h2,i,c,ii,cc]=poiindex(p,e,t,sd)

Description

`[n1,n2,h1,h2,i,c,ii,cc]=poiindex(p,e,t,sd)` identifies a given grid `p`, `e`, `t` in the subdomain `sd` as an evenly spaced rectangular grid. If the grid is not rectangular, `n1` is 0 on return. Otherwise `n1` and `n2` are the number of points in the first and second directions, `h1` and `h2` are the spacings. `i` and `ii` are of length `(n1-2)*(n2-2)` and contain indices of interior points. `i` contains indices of the original mesh, whereas `ii` contains indices of the canonical ordering. `c` and `cc` are of length `n1*n2-(n1-2)*(n2-2)` and contain indices of border points. `ii` and `cc` are increasing.

In the canonical ordering, points are numbered from "left to right" and then from "bottom to top." Thus if `n1=3` and `n2=5`, then `ii=[5 8 11]` and
`cc=[1 2 3 4 6 7 9 10 12 13 14 15]`.

See Also

`poisolv`, `poiasma`

| poicalc |  | poimesh |