Provided by: gmt-manpages_3.4.4-1_all 
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 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.
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)