Partial Differential Equation Toolbox |

pdecgrad

Returns the flux of a PDE solution

Syntax

-     [cgxu,cgyu]=pdecgrad(p,t,c,u)
      [cgxu,cgyu]=pdecgrad(p,t,c,u,time)
      [cgxu,cgyu]=pdecgrad(p,t,c,u,time,sdl)

Description

`[cgxu,cgyu]=pdecgrad(p,t,c,u)` returns the flux, c u, evaluated at the center of each triangle.

Row i of `cgxu` contains

Row i of `cgyu` contains

There is one column for each triangle in `t` in both `cgxu` and `cgyu`.

The geometry of the PDE problem is given by the mesh data `p` and t. Details on the mesh data representation can be found in the entry on `initmesh`.

The coefficient `c` of the PDE problem can be given in a variety of ways. A complete listing of all options can be found in the entry on `assempde`.

The format for the solution vector `u` is described in `assempde`.

The scalar optional argument `time` is used for parabolic and hyperbolic problems, if `c` depends on `t`, the time.

The optional argument `sdl` restricts the computation to the subdomains in the list `sdl`.

See Also

`assempde`

| pdebound |  | pdecirc |