A function to show the grid that will be used for a given cellwidth
showGrid(dat, cellwidth, ext = 2, boundingbox = NULL)
a plot showing the grid and the data. Ideally the data should only just fit inside the grid.
any spatial data object whose bounding box can be computed using the function bbox.
an initial suggested cellwidth
the extension parameter for the FFT transform, set to 2 by default
optional bounding box over which to construct computational grid, supplied as an object on which the function 'bbox' returns the bounding box