<!-- Creator : groff version 1.19.2 -->
<!-- CreationDate: Tue Mar 8 16:22:41 2011 -->
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta name="generator" content="groff -Thtml, see www.gnu.org">
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<meta name="Content-Style" content="text/css">
<style type="text/css">
p { margin-top: 0; margin-bottom: 0; }
pre { margin-top: 0; margin-bottom: 0; }
table { margin-top: 0; margin-bottom: 0; }
</style>
<title>GRDROTATER</title>
</head>
<body bgcolor="#ffffff">
<h1 align=center>GRDROTATER</h1>
<a href="#NAME">NAME</a><br>
<a href="#SYNOPSIS">SYNOPSIS</a><br>
<a href="#DESCRIPTION">DESCRIPTION</a><br>
<a href="#OPTIONS">OPTIONS</a><br>
<a href="#EXAMPLES">EXAMPLES</a><br>
<a href="#COORDINATES">COORDINATES</a><br>
<a href="#SEE ALSO">SEE ALSO</a><br>
<hr>
<a name="NAME"></a>
<h2>NAME</h2>
<p style="margin-left:11%; margin-top: 1em">grdrotater
− Rotate a grid using a finite rotation</p>
<a name="SYNOPSIS"></a>
<h2>SYNOPSIS</h2>
<p style="margin-left:11%; margin-top: 1em"><b>grdrotate</b>
<i>ingrdfile</i> <b>−G</b><i>outgrdfile</i>
<b>−T</b><i>plon</i>/<i>plat</i>/<i>omega</i> [
<b>−F</b><i>polygonfile</i> ] [
<b>−H</b>[<b>i</b>][<i>nrec</i>] ] [ <b>−N</b> ]
[
<b>−Q</b>[<b>b</b>|<b>c</b>|<b>l</b>|<b>n</b>][[<b>/</b>]<i>threshold</i>]
] [
<b>−R</b><i>west</i>/<i>east</i>/<i>south</i>/<i>north</i>[<b>r</b>]
] [ <b>−S</b> ] [ <b>−V</b> ] [
<b>−:</b>[<b>i</b>|<b>o</b>] ] [
<b>−b</b>[<b>i</b>|<b>o</b>][<b>s</b>|<b>S</b>|<b>d</b>|<b>D</b>[<i>ncol</i>]|<b>c</b>[<i>var1</i><b>/</b><i>...</i>]]
] [ <b>−m</b>[<i>flag</i>] ]</p>
<a name="DESCRIPTION"></a>
<h2>DESCRIPTION</h2>
<p style="margin-left:11%; margin-top: 1em"><b>grdrotater</b>
reads a geographical grid and reconstructs it given a total
reconstruction rotation. Optionally, the user may supply a
clipping polygon in multiple-segment format; then, only the
part of the grid inside the polygon is used to determine the
return grid region. The outline of the projected region is
returned on stdout provided the rotated region is not the
entire globe.</p>
<table width="100%" border=0 rules="none" frame="void"
cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="8%"></td>
<td width="7%"></td>
<td width="85%">
<p valign="top">No space between the option flag and the
associated arguments. Use upper case for the option flags
and lower case for modifiers.</p></td>
</table>
<p style="margin-left:11%;"><i>ingrdfile</i></p>
<p style="margin-left:22%;">Name of a grid file in
geographical (lon, lat) coordinates.</p>
<table width="100%" border=0 rules="none" frame="void"
cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="3%">
<p style="margin-top: 1em" valign="top"><b>−G</b></p> </td>
<td width="8%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Name of output
grid. This is the grid with the data reconstructed according
to the specified rotation.</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="3%">
<p style="margin-top: 1em" valign="top"><b>−T</b></p> </td>
<td width="8%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Finite rotation.
Specify the longitude and latitude of the rotation pole and
the opening angle, all in degrees.</p></td>
</table>
<a name="OPTIONS"></a>
<h2>OPTIONS</h2>
<table width="100%" border=0 rules="none" frame="void"
cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−F</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Specify a
multi-segment closed polygon file that describes the inside
area of the grid that should be projected [Default projects
entire grid].</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−H</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Input file(s) has
header record(s). If used, the default number of header
records is <b><A HREF="gmtdefaults.html#N_HEADER_RECS">N_HEADER_RECS</A></b>. Use <b>−Hi</b> if
only input data should have header records [Default will
write out header records if the input data have them]. Blank
lines and lines starting with # are always skipped.</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−N</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Do Not output the
rotated polygon outline [Default will write it to
stdout].</p> </td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−Q</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Quick mode, use
bilinear rather than bicubic interpolation [Default].
Alternatively, select the interpolation mode by adding
<b>b</b> for B-spline smoothing, <b>c</b> for bicubic
interpolation, <b>l</b> for bilinear interpolation or
<b>n</b> for nearest-neighbor value. Optionally, append
<i>threshold</i> in the range [0,1]. This parameter controls
how close to nodes with NaN values the interpolation will
go. E.g., a <i>threshold</i> of 0.5 will interpolate about
half way from a non-NaN to a NaN node, whereas 0.1 will go
about 90% of the way, etc. [Default is 1, which means none
of the (4 or 16) nearby nodes may be NaN]. <b>−Q0</b>
will just return the value of the nearest node instead of
interpolating. This is the same as using
<b>−Qn</b>.</p> </td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−R</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top"><i>west, east,
south,</i> and <i>north</i> specify the Region of interest,
and you may specify them in decimal degrees or in
[+-]dd:mm[:ss.xxx][W|E|S|N] format. Append <b>r</b> if lower
left and upper right map coordinates are given instead of
w/e/s/n. The two shorthands <b>−Rg</b> and
<b>−Rd</b> stand for global domain (0/360 and
-180/+180 in longitude respectively, with -90/+90 in
latitude). Alternatively, specify the name of an existing
grid file and the <b>−R</b> settings (and grid
spacing, if applicable) are copied from the grid.</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−S</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Skip the rotation
of the grid, just rotate the polygon outline (requires
<b>−F</b>).</p> </td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−V</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Selects verbose
mode, which will send progress reports to stderr [Default
runs "silently"].</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−:</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Toggles between
(longitude,latitude) and (latitude,longitude) input/output.
[Default is (longitude,latitude)].</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−bi</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Selects binary
input. Append <b>s</b> for single precision [Default is
<b>d</b> (double)]. Uppercase <b>S</b> or <b>D</b> will
force byte-swapping. Optionally, append <i>ncol</i>, the
number of columns in your binary input file if it exceeds
the columns needed by the program. Or append <b>c</b> if the
input file is netCDF. Optionally, append
<i>var1</i><b>/</b><i>var2</i><b>/</b><i>...</i> to specify
the variables to be read. [Default is 2 input columns].</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−bo</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Selects binary
output. Append <b>s</b> for single precision [Default is
<b>d</b> (double)]. Uppercase <b>S</b> or <b>D</b> will
force byte-swapping. Optionally, append <i>ncol</i>, the
number of desired columns in your binary output file.
[Default is same as input].</p></td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="4%">
<p style="margin-top: 1em" valign="top"><b>−m</b></p> </td>
<td width="7%"></td>
<td width="78%">
<p style="margin-top: 1em" valign="top">Multiple segment
file(s). Segments are separated by a special record. For
ASCII files the first character must be <i>flag</i> [Default
is ’>’]. For binary files all fields must be
NaN and <b>−b</b> must set the number of output
columns explicitly. By default the <b>−m</b> setting
applies to both input and output. Use <b>−mi</b> and
<b>−mo</b> to give separate settings to input and
output.</p> </td>
</table>
<a name="EXAMPLES"></a>
<h2>EXAMPLES</h2>
<p style="margin-left:11%; margin-top: 1em">To rotate the
data defined by grid topo.grd and the polygon outline
clip_path.d, using a finite rotation with pole at (135.5,
-33.0) and a rotation angle of 37.3 degrees and bicubic
interpolation, try</p>
<p style="margin-left:11%; margin-top: 1em"><b>grdrotater</b>
topo.grd <b>−T</b>135.5/-33/37.3 <b>−V
−F</b>clip_path.d <b>−G</b>rot_topo.grd >
rot_clip_path.d</p>
<p style="margin-left:11%; margin-top: 1em">To rotate the
entire grid faa.grd using a finite rotation pole at (67:45W,
22:35S) and a rotation angle of 19.6 degrees using a
bilinear interpolation, try</p>
<p style="margin-left:11%; margin-top: 1em"><b>grdrotater</b>
faa.grd <b>−T</b>67:45W/22:35S/19.6 <b>−V
−Q −G</b>rot_faa.grd > rot_faa_path.d</p>
<p style="margin-left:11%; margin-top: 1em">To just see how
the outline of the grid large.grd will plot after the same
rotation, try</p>
<p style="margin-left:11%; margin-top: 1em"><b>grdrotater</b>
large.grd <b>−T</b>67:45W/22:35S/19.6 <b>−V
−S</b> | psxy <b>−Rg −JH</b>180/6i
<b>−B</b>30 <b>−m −W</b>0.5<b>p</b> | gv
-</p>
<p style="margin-left:11%; margin-top: 1em">Let say you
have rotated gridA.grd and gridB.grd, restricting each
rotation to nodes inside polygons polyA.d and polyB.d,
respectively, using rotation A = (123W,22S,16,4) and
rotation B = (108W, 16S, -14.5), yielding rotated grids
rot_gridA.grd and rot_gridB.grd. To determine the region of
overlap between the rotated grids, we use grdmath:</p>
<p style="margin-left:11%; margin-top: 1em">grdmath 1
rot_gridA.grd ISNAN SUB 1 rot_gridB.grd ISNAN SUB 2 EQ =
overlap.grd</p>
<p style="margin-left:11%; margin-top: 1em">The grid
overlap.grd now has 1s in the regions of overlap and 0
elsewhere. You can use it as a mask or use grdcontour to
extract a polygon (contour).</p>
<a name="COORDINATES"></a>
<h2>COORDINATES</h2>
<p style="margin-left:11%; margin-top: 1em">Data
coordinates are assumed to be geodetic and will
automatically be converted to geocentric before spherical
rotations are performed. We convert back to geodetic
coordinates for output. Note: If your data already are
geocentric, you can avoid the conversion by using
--ELLIPSOID=sphere.</p>
<a name="SEE ALSO"></a>
<h2>SEE ALSO</h2>
<p style="margin-left:11%; margin-top: 1em"><i><A HREF="backtracker.html">backtracker</A></i>(1),
<i><A HREF="grdspotter.html">grdspotter</A></i>(1), <i><A HREF="hotspotter.html">hotspotter</A></i>(1),
<i><A HREF="originator.html">originator</A></i>(1) <i><A HREF="rotconverter.html">rotconverter</A></i>(1)</p>
<hr>
</body>
</html>
distrib
>
Fedora
>
13
>
x86_64
>
media
>
updates
>
by-pkgid
>
bde97f1793fb4b5ac4b6e6950d3353e2
>
files
>
960
