B.2.2.1 Grid line registration

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B.2.2.1 Grid line registration

In this registration, the nodes are centered on the grid line intersections and the data points represent the average value in a cell of dimensions ( $x_{inc} \cdot y_{inc}$ ) centered on the nodes (Figure B.1). In the case of grid line registration the number of nodes are related to region and grid spacing by

$\begin{displaymath}\begin{array}{ccl} nx & = & (x_{max} - x_{min}) / x_{inc} + 1 \\ ny & = & (y_{max} - y_{min}) / y_{inc} + 1 \end{array} \end{displaymath}$

which for the example in Figure B.1 yields .

**Figure B.1:** Grid line registration of data nodes
$\begin{figure}\centering\epsfig{figure=eps/GMT_gridreg.eps}\end{figure}$

Paul Wessel 2001-04-18