.TH GRDPASTE 1gmt "Feb 27 2014" "GMT 4.5.13 (SVN)" "Generic Mapping Tools"
.SH NAME
grdpaste \- Paste together two \fI.grd\fP files along a common edge.
.SH SYNOPSIS
\fBgrdpaste\fP \fIfile_a.grd file_b.grd\fP \fB\-G\fP\fIoutfile.grd\fP [ \fB\-V\fP ] [ \fB\-f\fP[\fBi\fP|\fBo\fP]\fIcolinfo\fP ]
.SH DESCRIPTION
\fBgrdpaste\fP will combine \fIfile_a.grd\fP and \fIfile_b.grd\fP into \fIoutfile.grd\fP by pasting
them together along their common edge.  Files \fIfile_a.grd\fP and \fIfile_b.grd\fP must have the same dx, dy and have one edge
in common.  If in doubt, check with \fBgrdinfo\fP and use \fBgrdcut\fP and/or \fBgrdsample\fP
if necessary to prepare the edge joint.  For geographical grids, use \fB\-f\fP to handle periodic longitudes.
.TP
\fIfile_a.grd\fP
One of two files to be pasted together.
.TP
\fIfile_b.grd\fP
The other of two files to be pasted together.
.TP
\fB\-G\fP\fIoutfile.grd\fP
The name for the combined output.
.SH OPTIONS
.TP
\fB\-V\fP
Selects verbose mode, which will send progress reports to stderr [Default runs "silently"].
.TP
\fB\-f\fP
Special formatting of input and/or output columns (time or geographical data).
Specify \fBi\fP or \fBo\fP 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 \fBT\fP (absolute calendar time), \fBt\fP (relative time in chosen \fBTIME_UNIT\fP since \fBTIME_EPOCH\fP),
\fBx\fP (longitude), \fBy\fP (latitude), or \fBf\fP (floating point) to each column
or column range item.  Shorthand \fB\-f\fP[\fBi\fP|\fBo\fP]\fBg\fP means \fB\-f\fP[\fBi\fP|\fBo\fP]0\fBx\fP,1\fBy\fP
(geographic coordinates).
.SH GRID FILE FORMATS
By default \fBGMT\fP writes out grid as single precision floats in a COARDS-complaint netCDF file format.
However, \fBGMT\fP is able to produce grid files in many other commonly used grid file formats and also facilitates so called "packing" of grids,
writing out floating point data as 2- or 4-byte integers. To specify the precision, scale and offset, the user should add the suffix
\fB=\fP\fIid\fP[\fB/\fP\fIscale\fP\fB/\fP\fIoffset\fP[\fB/\fP\fInan\fP]], where \fIid\fP is a two-letter identifier of the grid type and precision, and \fIscale\fP and \fIoffset\fP are optional scale factor
and offset to be applied to all grid values, and \fInan\fP is the value used to indicate missing data.
When reading grids, the format is generally automatically recognized. If not, the same suffix can be added to input grid file names.
See \fBgrdreformat\fP(1) and Section 4.17 of the GMT Technical Reference and Cookbook for more information.
.P
When reading a netCDF file that contains multiple grids, \fBGMT\fP will read, by default, the first 2-dimensional grid that can find in that
file. To coax \fBGMT\fP into reading another multi-dimensional variable in the grid file, append \fB?\fP\fIvarname\fP to the file name, where
\fIvarname\fP is the name of the variable. Note that you may need to escape the special meaning of \fB?\fP in your shell program
by putting a backslash in front of it, or by placing the filename and suffix between quotes or double quotes.
The \fB?\fP\fIvarname\fP suffix can also be used for output grids to specify a variable name different from the default: "z".
See \fBgrdreformat\fP(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.
.SH EXAMPLES
Suppose file_a.grd is 150E - 180E and 0 - 30N, and file_b.grd is 150E - 180E, -30S - 0, then you can
make outfile.grd which will be 150 - 180 and -30S - 30N by: 
.sp
\fBgrdpaste\fP file_a.grd file_b.grd \fB\-G\fP outfile.grd \fB\-V\fP \fB\-fg\fP
.SH "SEE ALSO"
.IR GMT (1),
.IR grdcut (1),
.IR grdinfo (1),
.IR grdsample (1)