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:

\[ \begin{align}\begin{aligned}\begin{bmatrix} 1 & & & & \\1/2 & 1/2 & & & \\& 1/2 & 1/2 & & & \\& & \ddots & \ddots & \\& & & 1/2 & 1/2 \\& & & & 1 \; \end{bmatrix}\end{aligned}\end{align} \]

Parameters

nint

Number of cells

Returns

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

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