Partial Differential Equation Toolbox |

tri2grid

Interpolate from PDE triangular mesh to rectangular grid

Syntax

-     uxy=tri2grid(p,t,u,x,y)
      [uxy,tn,a2,a3]=tri2grid(p,t,u,x,y)
      uxy=tri2grid(p,t,u,tn,a2,a3)

Description

`uxy=tri2grid(p,t,u,x,y)` computes the function values `uxy` over the grid defined by the vectors `x` and `y`, from the function `u` with values on the triangular mesh defined by `p` and t. Values are computed using linear interpolation in the triangle containing the grid point. The vectors `x` and `y` must be increasing.

`[uxy,tn,a2,a3]=tri2grid(p,t,u,x,y)` additionally lists the index `tn` of the triangle containing each grid point, and interpolation coefficients `a2` and `a3`.

`uxy=tri2grid(p,t,u,tn,a2,a3)` , with `tn`, `a2`, and `a3` computed in an earlier call to `tri2grid`, interpolates using the same grid as in the earlier call. This variant is, however, much faster if several functions have to be interpolated using the same grid.

For grid points outside of the triangular mesh, `NaN` is returned in `uxy`, `tn`, `a2`, and `a3`.

See Also

`initmesh`, `refinemesh`, `assempde`

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