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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 $nx = ny = 4$.

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


next up previous contents index
Next: B.2.2.2 Pixel registration Up: B.2.2 Grid line and Previous: B.2.2 Grid line and   Contents   Index
Paul Wessel 2004-10-01