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<h2>stnmap</h2>
<code>stnmap [ -<i>i fname</i> ]</code><p>
<h3>Usage Notes</h3>
<code>stnmap</code> is a GrADS utility that writes out a hash
table
and/or link list information for station data that allows
GrADS to access the report data more efficiently.
<p>
If you change the data file - perhaps by appending another
time group - you will also have to change the descriptor
file to reflect the changes - the new number of times for
example - and then rerun the <code>stnmap</code> utility.
<p>
Note the difference between station descriptor file and a
grid descriptor file:<p>
<ul>
<code>DTYPE</code> specify a data
type of: station<p>
<code>STNMAP</code> gives the file
name of the station mapping file. <p>
<code>XDEF, YDEF, ZDEF</code> not
specified.<p>
<code>TDEF</code> describes the
time grouping interval and
the number of the time groups in the
file.<p>
<code>VAR</code> surface
variables must come first, and
are given a zero for the
number-of-levels field. Level dependent
variables are listed after the surface
variables, and are given a one in the
number-of-levels field.</ul><p>
<h3>Examples</h3>
When a data set, for example <code>ua.reps</code> is written, and
the
descriptor file <code>stat.ctl</code>, including the information
records
for the station data file <code>ua.reps</code> is created, you
should
then create the station map file <code>ua.map</code> (named in the
<code>STNMAP</code>
record of the descriptor file; see below) by running the
<code>stnmap</code> utility.<p>
Example descriptor file: <code>stat.ctl</code>
<ul>
<code>
DSET ^ua.reps<br>
DTYPE station<br>
STNMAP ^ua.map<br>
UNDEF -999.0<br>
TITLE Real Time Upper air obs<br>
TDEF 10 linear 12z18jan1992 12hr<br>
VARS 12<br>
slp 0 99 SLP<br>
ts 0 99 Temps<br>
us 0 99 U Winds<br>
vs 0 99 V Winds<br>
z 1 99 Heightsa<br>
t 1 99 Temps<br>
u 1 99 U Winds<br>
v 1 99 V WInds<br>
ENDVARS</code></ul><p>
Running the <code>stnmap</code> utility:<p>
<dd> <code>stnmap -i stat.ctl</code><p>
The station map file <code>ua.map</code> is a binary file, which
includes
the hash table and/or link list information.
