Compute the min/max values of the first n columns to the nearest multiple of the provided increments (separate the n increments by slashes) [default is 2 columns]. By default, output results in the form -Rw/e/s/n, unless -C is set in which case we output each min and max value in separate output columns. If only one increment is given we also use it for the second column (for backwards compatibility). To override this behavior, use -Ipdx. If the input x- and y-coordinates all have the same phase shift relative to the dx and dy increments then we use those phase shifts in determining the region, and you may use -rreg to switch from gridline-registration to pixel-registration. For irregular data both phase shifts are set to 0 and the -rreg is ignored. Use -Ifdx[/dy] to report an extended region optimized to give grid dimensions for fastest results in programs using FFTs. Use -Isdx[/dy] to report an extended region optimized to give grid dimensions for fastest results in programs like surface. Use -Ib to write the bounding box of the data table or segments (see -A) as a closed polygon segment. Note: For oblique projections you should use the -Ap option in plot to draw the box properly. If -Ie is given then the exact min/max of the input is given in the -R string. If you only want either the x-* or y- range to be exact and the other range rounded, give one of the increments as zero. Append +r to modify the min/max of the first n columns further: Append inc, xinc/yinc, or winc/einc/sinc/ninc to adjust the region to be a multiple of these steps [no adjustment]. Alternatively, use +R to extend the region outward by adding these increments instead, or +e which is like +r but it ensures that the bounding box extends by at least 0.25 times the increment [no extension].
it would be best to one day create a separate -I documentation page, with
minimal individual examples of each one of these features in action,
to ensure they can all be understood.
Next time the author should create a separate side page, with minimal
individual examples of each item (50 here?). Else there is risk that his
original meaning might be forever lost, as others might have difficulty
(P.S., gmtinfo -I can give
So one needs to do
set -- $(... gmt info -I... -C) myR=-R$1/$3/$2/$4+r
Yes, I saw
For oblique projections you should use the -Ap option in plot to draw the box properly.
but I wasn’t using plot today.)