# $Id: grdraster.info,v 1.5 2010/10/28 21:48:43 guru Exp $ # # This file contains information on rasterfiles which are readable with grdraster. # This file must be named grdraster.info. At run time, grdraster will look for # this file in $GMT_USERDIR (which defaults to ~/.gmt), $GMT_GRIDDIR, and # $GMT_SHAREDIR/dbase (in that order). Any line beginning with a # will be # treated as a comment, and blank lines are skipped. Any other line must have # the following items, all on one line, one line, pertaining to one rasterfile: # # file_number "title string" "z units" -R -I GorP type scale offset NaNflag filename [L|B] [H<bytes>] # # There must be white space between each item. "title string" and "z units" must # be enclosed in " ", and they may have white space within them. They are limited # to a maximum of 80 characters. No other quotation marks should be on a line. # The entire line should be writable in 320 characters. # # file_number is an integer used to tell grdraster which raster to read. It must # be unique to each raster. # "title string" is a brief description of the data. # "z units" describes the units of the data after they are scaled and offset. # -R<w>/<e>/<s>/<n> describes the range of the raster in the usual GMT -R manner. # -I<x_inc>/<y_inc> describes the sampling interval in the usual GMT -I manner. # GorP is either G or P, indicating Grid or Pixel registration. Optionally, you # can append G (Geographic) or C (Cartesian) to explicitly set this attribute # which would otherwise be guessed based on the x/y range # type is one of the following, indicating the kind of data stored in the raster: # b bit data, either 0 or 1, one bit per data value. # u unsigned character data. # c signed character data. # d unsigned two-byte integer data. # i signed two-byte integer data. # l signed four-byte integer data. # scale is a number which should be multiplied on the raster value after read. # offset is a number which should be added to the [scaled] raster value. # NaNflag is a number which is written in the raster to represent NaN. # If all values in the raster represent data, NaNflag is none. # filename is the name the raster file. If filename begins with a "/", then # it will be treated as a complete name. If not, the complete name will # be formed as $(GMT_GRIDDIR)/filename. # # BYTE-ORDER: # # Optionally, you may append a single character L (for Little-endian) or B (for # Big-endian) to indicate the endian-ness of this data file. If the present # endianness of your computer has a different endianness that specified for the # chosen data set, then grdraster will automatically swap the bytes. The # endianness of your computer is automatically determined at compile-time. # # You will need to edit this to reflect which data you have installed on your # system, and optionally append L or B to indicate endian-ness: # # Finally, if your raster grid has a header you can specify the size of the header # in bytes and grdraster will skip these bytes before reading the data 1 "ETOPO5 global topography" "m" -R0/359:55/-90/90 -I5m GG i 1 0 none etopo5.i2 2 "US Elevations from USGS" "m" -R234/294/24/50 -I0.5m PG i 0.3048 0 -9999 us_topo30s.i2 3 "Geosat/Seasat gravity from Haxby" "mGal" -R0/360/-90/90 -I5m GG i 0.1 0 none haxby5m_faa.i2 4 "Geosat/Seasat geoid from Haxby" "m" -R0/360/-90/90 -I5m GG i 0.001 0 none haxby5m_geoid.i2 5 "Sea floor age from Cande" "Ma" -R0/360/-90/90 -I5m PG i 0.1 0 -30000 cande5m_ages.i2 6 "Sea floor age from Muller" "Ma" -R0/360/-72/72 -I6m GG i 0.01 0 32767 scripps6m_ages.i2 7 "1=land, 0=sea bitmask" "T/F" -R0/360/-90/90 -I5m PG b 1 0 none landsea.bits
