XYZ2GRD(l)																XYZ2GRD(l)

NAME

       xyz2grd - Converting an ASCII or binary table to grd file format

SYNOPSIS

       xyz2grd	xyzfile -Ggrdfile -Ix_inc[m|c][/y_inc[m|c]] -Rwest/east/south/north[r] [ -A[n|z] ] [ -Dxunit/yunit/zunit/scale/offset/title/remark
       ] [ -F ] [ -H[nrec] ] [ -L ] [ -Nnodata ] [ -S[zfile] ] [ -V ] [ -Z[flags] ] [ -: ] [ -bi[s][n] ]

DESCRIPTION

       xyz2grd reads a z or xyz table and creates a binary grdfile. xyz2grd will report if some of the nodes are not filled  in  with  data.  Such
       unconstrained  nodes  are set to a value specified by the user [Default is NaN].  Nodes with more than one value will be set to the average
       value. As an option (using -Z), a 1-column z-table may be read assuming all nodes are present (z-tables can be in organized in a number	of
       formats, see -Z below.)

       [xy]zfile
	      ASCII  [or binary] file holding z or (x,y,z) values. xyz triplets do not have to be sorted (for binary triplets, see -b). 1-column z
	      tables must be sorted and the -Z must be set).

       -G     grdfile is the name of the binary output grdfile.

       -I     x_inc [and optionally y_inc] is the grid spacing. Append m to indicate minutes or c to indicate seconds.

       -R     west, east, south, and north specify the Region of interest. To specify boundaries in degrees and minutes  [and  seconds],  use  the
	      dd:mm[:ss] format. Append r if lower left and upper right map coordinates are given instead of wesn.

OPTIONS

       -A     Add  up  multiple  values  that belong to the same node (same as -Az).  Append n to simply count the number of data points that were
	      assigned to each node.  [Default (no -A option) will calculate mean value]. Ignored if -Z is given.

       -D     Give values for xunit, yunit, zunit, scale, offset, title, and remark.  To leave some of these values untouched, specify	=  as  the
	      value.

       -F     Force pixel registration [Default is grid registration].

       -H     Input  file(s) has Header record(s). Number of header records can be changed by editing your .gmtdefaults file. If used, GMT default
	      is 1 header record.  Not used with binary data.

       -L     Indicates that the x column contains longitudes, which may differ from the regions in -R by  [multiples  of]  360  degrees  [Default
	      assumes no periodicity].

       -N     No  data.  Set nodes with no input xyz triplet to this value [Default is NaN]. For z-tables, this option is used to replace z-values
	      that equal nodata with NaN.

       -S     Swap the byte-order of the input only. No grid file is produced. You must also supply the -Z option. The output is written to  zfile
	      (or stdout if not supplied).

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

       -Z     Read a 1-column ASCII [or binary] table. This assumes that all the nodes are present and sorted according to specified ordering con-
	      vention contained in flags.  If incoming data represents rows, make flags start with T(op) if first row is y = ymax or  B(ottom)	if
	      first  row  is y = ymin. Then, append L or R to indicate that first element is at left or right end of row. Likewise for column for-
	      mats: start with L or R to position first column, and then append T or B to position first element in a row.   For  gridline  regis-
	      tered  grids:  If data are periodic in x but the incoming data do not contain the (redundant) column at x = xmax, append x. For data
	      periodic in y without redundant row at y = ymax, append y. Append sn to skip the first n number of bytes (probably a header). If the
	      byte-order needs to be swapped, append w. Select one of several data types (all binary except a):

		      a ASCII representation
		      c signed 1-byte character
		      u unsigned 1-byte character
		      h short 2-byte integer
		      i 4-byte integer
		      l long (4- or 8-byte) integer
		      f 4-byte floating point single precision
		      d 8-byte floating point double precision

	      Default format is scanline orientation of ASCII numbers: -ZTLa.  Note that -Z only applies to 1-column input.

       -:     Toggles  between	(longitude,latitude)  and  (latitude,longitude)  input/output. [Default is (longitude,latitude)].  Applies to geo-
	      graphic coordinates only.

       -bi    Selects binary input. Append s for single precision [Default is double].	Append n for the number of columns in the binary  file(s).
	      [Default is 3 input columns]. This option only applies to xyz input files; see -Z for z tables.

EXAMPLES

       To create a grdfile from the ASCII data in hawaii_grv.xyz, try

       xyz2grd hawaii_grv.xyz -Ddegree/degree/mGal/1/0/"Hawaiian Gravity"/"GRS-80 Ellipsoid used" -Ghawaii_grv_new.grd -R198/208/18/25 -I5m -V

       To create a grdfile from the raw binary (3-column, single-precision) scanline-oriented data raw.b, try

       xyz2grd raw.b -Dm/m/m/1/0/=/= -Graw.grd -R0/100/0/100 -I1 -V -Z -b3

       To  make  a grdfile from the raw binary USGS DEM (short integer) scanline-oriented data topo30. on the NGDC global relief Data CD-ROM, with
       values of -9999 indicate missing data, one must on some machine reverse the byte-order. On such machines (like Sun), try

       xyz2grd topo30. -Dm/m/m/1/0/=/= -Gustopo.grd -R234/294/24/50 -I30c -N-9999 -V -ZTLhw

       Say you have received a binary file with 4-byte floating points that were written on a machine of different byte-order than yours. You  can
       swap the byte-order with

       xyz2grd floats.bin -Snew_floats.bin -V -Zf

SEE ALSO

       gmt(1gmt), grd2xyz(1gmt), grdedit(1gmt)

								    1 Jan 2004								XYZ2GRD(l)