1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
<HTML>
<HEAD>
<TITLE>grdmask</TITLE>
</HEAD>
<BODY>
<H1>grdmask</H1>
<HR>
<PRE>
<!-- Manpage converted by man2html 3.0.1 -->
grdmask - Create mask grdfiles from xy paths.
</PRE>
<H2>SYNOPSIS</H2><PRE>
<B>grdmask</B> <I>pathfiles</I> <B>-G</B><I>mask</I><B>_</B><I>grd</I><B>_</B><I>file</I>] <B>-I</B><I>xinc</I>[<B>m|c</B>][/<I>yinc</I>[<B>m|c</B>]]
<B>-R</B><I>west/east/south/north</I>[<I>r</I>] [ <B>-F</B> ] [ <B>-H</B>[<I>nrec</I>] ] [ <B>-L</B> ] [
<B>-M</B>[<I>flag</I>] ] [ <B>-N</B><I>out/edge/in</I> ] [ <B>-S</B>[<I>radius</I>][<B>k</B>] ] [ <B>-V</B> ] [ <B>-:</B>
] [ <B>-bi</B>[<B>s</B>][<I>n</I>] ]
</PRE>
<H2>DESCRIPTION</H2><PRE>
<B>grdmask</B> can operate in 2 different modes. 1. It reads one
or more xy-files that each define a closed polygon. The
nodes defined by the specified region and lattice spacing
will be set equal to one of three possible values depend
ing on whether the node is outside, on the polygon perime
ter, or inside the polygon. The resulting mask grdfile may
be used in subsequent operations involving <B><A HREF="grdmath.html">grdmath</A></B> to mask
out data from polygonal areas. 2. The xy-files simply rep
resent data point locations and the mask is set to the
inside or outside value depending on whether a node is
within a maximum distance from the nearest data point. If
the distance specified is zero then only the nodes nearest
each data point are considered "inside".
<I>pathfiles</I>
The name of 1 or more ASCII [or binary, see <B>-b</B>]
files holding the polygon(s) or data points.
<B>-G</B> Name of resulting output mask grd file.
<B>-I</B> <I>x</I><B>_</B><I>inc</I> [and optionally <I>y</I><B>_</B><I>inc</I>] is the grid spacing.
Append <B>m</B> to indicate minutes or <B>c</B> to indicate sec
onds.
<B>-R</B> <I>west,</I> <I>east,</I> <I>south,</I> and <I>north</I> specify the Region of
interest. To specify boundaries in degrees and min
utes [and seconds], use the dd:mm[:ss] format.
Append <B>r</B> if lower left and upper right map coordi
nates are given instead of wesn.
</PRE>
<H2>OPTIONS</H2><PRE>
<B>-F</B> Force pixel registration. [Default is grid regis
tration].
<B>-H</B> Input file(s) has Header record(s). Number of
header records can be changed by editing your .gmt
defaults file. If used, <B><A HREF="GMT.html">GMT</A></B> default is 1 header
record.
<B>-L</B> Indicates that the x column contains longitudes,
which may differ from the regions in <B>-R</B> by [multi
ples of] 360 degrees [Default assumes no periodic
ity].
record whose first character is <I>flag</I>. [Default is
'>'].
<B>-N</B> Sets the values that will be assigned to nodes that
are <I>out</I>side the polygons, on the <I>edge</I>, or <I>in</I>side.
Values can be any number, including the textstring
NaN [Default is 0/0/1].
<B>-S</B> Set nodes depending on their distance from the
nearest data point. Nodes within <I>radius</I> [0] from a
data point are considered inside. Append <B>k</B> to indi
cate map units (e.g., <B>-R</B> <B>-I</B> in degrees and <I>radius</I>
in km).
<B>-V</B> Selects verbose mode, which will send progress
reports to stderr [Default runs "silently"].
<B>-bi</B> Selects binary input. Append <B>s</B> for single precision
[Default is double]. Append <I>n</I> for the number of
columns in the binary file(s). [Default is 2 input
columns].
</PRE>
<H2>EXAMPLES</H2><PRE>
To set all nodes inside and on the polygons coastline_*.xy
to 0, and outside points to 1, do
grdmask coastline_*.xy <B>-R</B>-60/-40/-40/-30 <B>-I</B>5<B>m</B> <B>-N</B>1/0/0
<B>-G</B>land_mask.grd <B>-V</B>
To set nodes within 50 km of data points to 1 and other
nodes to NaN, do
grdmask data.xyz <B>-R</B>-60/-40/-40/-30 <B>-I</B>5m <B>-N</B>NaN/1/1 <B>-S</B>50<B>k</B>
<B>-G</B>data_mask.grd <B>-V</B>
</PRE>
<H2>SEE ALSO</H2><PRE>
<I>gmt</I>(l), <I><A HREF="grdlandmask.html">grdlandmask</A></I>(l), <I><A HREF="grdmath.html">grdmath</A></I>(l), <I><A HREF="grdclip.html">grdclip</A></I>(l), <I><A HREF="psmask.html">psmask</A></I>(l),
<I><A HREF="psclip.html">psclip</A></I>(l)
</PRE>
<HR>
<ADDRESS>
Man(1) output converted with
<a href="http://www.oac.uci.edu/indiv/ehood/man2html.html">man2html</a>
</ADDRESS>
</BODY>
</HTML>
<body bgcolor="#ffffff">
|
