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GRDINFO(1)                   Generic Mapping Tools                  GRDINFO(1)

NAME
       grdinfo - Get information about the contents of a 2-D grid file

SYNOPSIS
       grdinfo grdfiles [ -C ] [ -F ] [ -I[dx[/dy]] ][ -L[0|1|2] ] [ -M ] [
       -Tdz ] [ -V ] [ -f[i|o]colinfo ]

DESCRIPTION
       grdinfo reads a 2-D binary grid file and reports various statistics for
       the (x,y,z) data in the grid file(s).  The output information contains
       the minimum/maximum values for x, y, and z, where the min/max of z
       occur, the x- and y-increments, and the number of x and y nodes, and
       [optionally] the mean, standard deviation, and/or the median, L1 scale
       of z, and number of nodes set to NaN.

       grdfile
              The name of one or several 2-D grid files.  (See GRID FILE
              FORMATS below.)

OPTIONS
       No space between the option flag and the associated arguments.

       -C     Formats the report using tab-separated fields on a single line.
              The output is w e s n z0 z1 dx dy nx ny [ x0 y0 x1 y1 ] [ med
              scale ] [ mean std rms] [n_nan].  The data in brackets are
              output only if the corresponding options -M, -L1, -L2, and -M
              are used, respectively.  If the -I option is used, the output
              format is instead NF w e s n z0 z1, where NF is the total number
              of grids read and w e s n are rounded off (see -I).

       -F     Report grid domain and x/y-increments in world mapping format
              [Default is generic].  Does not apply to the -C option.

       -I     Report the min/max of the region to the nearest multiple of dx
              and dy, and output this in the form -Rw/e/s/n (unless -C is
              set).  To report the actual grid region, select -I-.  If no
              argument is given then we report the grid increment in the form
              -Ixinc/yinc.

       -L0    Report range of z after actually scanning the data, not just
              reporting what the header says.

       -L1    Report median and L1 scale of z (L1 scale = 1.4826 * Median
              Absolute Deviation (MAD)).

       -L2    Report mean, standard deviation, and rms of z.

       -M     Find and report the location of min/max z-values, and count and
              report the number of nodes set to NaN, if any.

       -T     Determine min and max z-value, round off to multiples of dz, and
              report as the text string -Tzmin/zmax/dz for use by makecpt.

       -V     Selects verbose mode, which will send progress reports to stderr
              [Default runs "silently"].

       -f     Special formatting of input and/or output columns (time or
              geographical data).  Specify i or o to make this apply only to
              input or output [Default applies to both].  Give one or more
              columns (or column ranges) separated by commas.  Append T
              (absolute calendar time), t (relative time in chosen TIME_UNIT
              since TIME_EPOCH), x (longitude), y (latitude), or f (floating
              point) to each column or column range item.  Shorthand -f[i|o]g
              means -f[i|o]0x,1y (geographic coordinates).

GRID FILE FORMATS
       GMT is able to recognize many of the commonly used grid file formats,
       as well as the precision, scale and offset of the values contained in
       the grid file. When GMT needs a little help with that, you can add the
       suffix =id[/scale/offset[/nan]], where id is a two-letter identifier of
       the grid type and precision, and scale and offset are optional scale
       factor and offset to be applied to all grid values, and nan is the
       value used to indicate missing data.  See grdreformat(1) and Section
       4.17 of the GMT Technical Reference and Cookbook for more information.

       When reading a netCDF file that contains multiple grids, GMT will read,
       by default, the first 2-dimensional grid that can find in that file. To
       coax GMT into reading another multi-dimensional variable in the grid
       file, append ?varname to the file name, where varname is the name of
       the variable. Note that you may need to escape the special meaning of ?
       in your shell program by putting a backslash in front of it, or by
       placing the filename and suffix between quotes or double quotes.  See
       grdreformat(1) and Section 4.18 of the GMT Technical Reference and
       Cookbook for more information, particularly on how to read splices of
       3-, 4-, or 5-dimensional grids.

EXAMPLES
       To obtain all the information about the data set in file
       hawaii_topo.grd:

       grdinfo -L1 -L2 -M hawaii_topo.grd

SEE ALSO
       GMT(1), grd2cpt(1), grd2xyz(1), grdedit(1)

GMT 4.5.14                        1 Nov 2015                        GRDINFO(1)