SimPEG.utils.av_extrap

SimPEG.utils.av_extrap(n)

Create 1D averaging operator from cell-centers to nodes.

For n cells, the 1D averaging operator from cell centers to nodes is sparse and has shape (n+1, n). Values at the outmost nodes are extrapolated from the nearest cell center value. Thus the operator takes the form:

$$\begin{array}{r}\begin{array}{c}\left[\begin{array}{ccccc}1& & & & \\ 1/2& 1/2& & & \\ & 1/2& 1/2& & & \\ & & \ddots & \ddots & \\ & & & 1/2& 1/2\\ & & & & 1\end{array}\right]\end{array}\end{array}$$

Parameters

nint

Number of cells

Returns

(n+1, n) scipy.sparse.csr_matrix

The 1D averaging operator from cell-centers to nodes.