.TH GRD2XYZ l "1 Jan 2004"
.SH NAME
grd2xyz \- Converting a grdfile to an ASCII or binary table
.SH SYNOPSIS
\fBgrd2xyz\fP \fIgrdfile\fP [ \fB\-H\fP[\fInrec\fP] ] [ \fB\-L\fP ] [ \fB\-R\fP\fIwest/east/south/north\fP[\fBr\fP]
[ \fB\-S\fP[\fBr\fP ] [ \fB\-V\fP ] [ \fB\-Z\fP[\fIflags\fP] ] [ \fB\-bo\fP[\fBs\fP][\fIn\fP] ]
.SH DESCRIPTION
\fBgrd2xyz\fP reads a binary 2-D grdfile and writes out xyz-triplets in ASCII [or binary] format to standard output.
Modify the
precision of the ASCII output format by editing the D_FORMAT parameter in your .gmtdefaults file, or
choose binary output using single or double precision storage. As an option you may output
z-values without the (x,y) in a
number of formats, see \fB\-Z\fP below.
.TP
\fIgrdfile\fP
The 2-D binary file to be converted.
.SH OPTIONS
.TP
.B \-H
Output 1 header record based on information in the grdfile header.
Ignored if binary output is selected. [Default is no header].
.TP
.B \-L
Indicates that the x values are longitudes (necessary for \fB\-:\fP to work).
.TP
.B \-R
\fIwest, east, south,\fP and \fInorth\fP specify the Region of interest. To specify boundaries
in degrees and minutes [and seconds], use the dd:mm[:ss] format. Append \fBr\fP if lower left and upper right
map coordinates are given instead of wesn.
.TP
.B \-S
Suppress output for nodes whose z-value equals NaN [Default outputs all nodes].
Append \fBr\fP to reverse the suppression, i.e., only output the nodes whose
z-value equals NaN.
.TP
.B \-V
Selects verbose mode, which will send progress reports to stderr [Default runs "silently"].
.TP
.B \-Z
Write a 1-column ASCII [or binary] table. Output will be organized according to the specified ordering convention contained in \fIflags\fP.
If data should be written by rows, make \fIflags\fP start with \fBT\fP(op) if first row is y = ymax
or \fBB\fP(ottom) if first row is y = ymin. Then, append \fBL\fP or \fBR\fP to indicate that first element should start at left
or right end of row. Likewise for column formats: start with \fBL\fP or \fBR\fP to position first column,
and then append \fBT\fP or \fBB\fP to position first element in a row.
For gridline registered grids: If grid is periodic in x but the
outcoming data should not contain the (redundant) column at x = xmax, append \fBx\fP. For grid periodic in y,
skip writing the redundant row at y = ymax by appending \fBy\fP. If the byte-order needs to be swapped, append \fBw\fP. Select
one of several data types (all binary except \fBa\fP):
.br
.sp
        \fBa\fP ASCII representation
.br
        \fBc\fP signed 1-byte character
.br
        \fBu\fP unsigned 1-byte character
.br
        \fBh\fP short 2-byte integer
.br
        \fBi\fP 4-byte integer
.br
        \fBl\fP long (4- or 8-byte) integer
.br
        \fBf\fP 4-byte floating point single precision
.br
        \fBd\fP 8-byte floating point double precision
.br
.sp
Default format is scanline orientation of ASCII numbers: \fB\-ZTLa\fP.
Note that \fB\-Z\fP only applies to 1-column output.
.TP
.B \-bo
Selects binary output. Append \fBs\fP for single precision [Default is double].
This option only applies to xyz output; see \fB\-Z\fP for z table output.
.SH EXAMPLES
To edit individual values in the 5' by 5' hawaii_grv.grd file, try
.br
.sp
grd2xyz hawaii_grv.grd > hawaii_grv.xyz
.br
.sp
To write a single precision binary file without the x,y positions from the file raw_data.grd file, using scanline orientation, try
.br
.sp
grd2xyz raw_data.grd \fB\-ZTLf\fP > hawaii_grv.b
.SH "SEE ALSO"
.IR gmtdefaults (1gmt),
.IR gmt (1gmt),
.IR grdedit (1gmt),
.IR xyz2grd (1gmt)