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B.2.2.2 Pixel registration

Here, the nodes are centered in the grid cells, i.e., the areas between grid lines, and the data points represent the average values within each cell (Figure B.2. In the case of pixel 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} \\
ny & = & (y_{max} - y_{min}) / y_{inc}
\end{array} \end{displaymath}

Thus, given the same region (-R), the pixel registered grids have one less column and one less row than the grid line registered grids; here we find $nx = ny = 3$.

Figure B.2: Pixel registration of data nodes.
\begin{figure}\centering\epsfig{figure=eps/GMT_pixelreg.eps}\end{figure}


next up previous contents index
Next: B.2.3 Boundary Conditions for Up: B.2.2 Grid line and Previous: B.2.2.1 Grid line registration   Contents   Index
Paul Wessel 2004-10-01