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


       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] ]


       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.)

              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.


       -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

       -Z     Read  a  1-column  ASCII  [or  binary]  table.  This assumes that all the nodes are
              present and sorted according to specified ordering convention 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 formats: start
              with L or R to position first column, and then append T  or  B  to  position  first
              element in a row.  For gridline registered 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 geographic 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.


       To create a grdfile from the ASCII data in, try

       xyz2grd -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


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

                                            1 Jan 2004                                 XYZ2GRD(l)