<!--Copyright (C) 1988-2005 by the Institute of Global Environment and Society (IGES). See file COPYRIGHT for more information.--> <html> <title>GrADS Utilities: stnmap</title> <body bgcolor="e0f0ff" text="000000"> <h2><a name="stnmap">stnmap</a></h2> <code>stnmap [-i <i>fname</i>] [-0]</code> <p> <code>stnmap</code> is an external GrADS utility that writes out a hash table and/or link list information for station data that allows GrADS to access the data more efficiently. After a station data set has been written and the accompanying data descriptor file has been created, you must run the <code>stnmap</code> utility before you can look at the data in GrADS. <p> The <code>stnmap</code> options are as follows: <ul> <code><i>fname</i></code> <ul>The name of the station data descriptor file. If not specified, <code>stnmap</code> will prompt the user.</ul> <p> <code>-0</code> <ul>Allows processing of certain templated station data sets without actually reading the data.</ul> </ul> <p> The output from <code>stnmap</code> goes into a file that is named in the <code>STNMAP</code> record of the data descriptor file. (See Usage Note #2). <p> <b>Usage Notes</b> <ol> <li>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 and then rerun the <code>stnmap</code> utility. <p> <li>Note the difference between required records in a station descriptor file and a grid descriptor file: <p> <code>DTYPE</code> <ul>specifies a data type of: station</ul> <code>STNMAP</code> <ul>gives the file name of the station mapping file</ul> <code>XDEF, YDEF, ZDEF</code> <ul>these records are not specified in a station data control file</ul> <code>TDEF</code> <ul>describes the time grouping interval and the number of the time groups in the file</ul> <code>VARS</code> <ul> surface variables are listed first, and show a "0" for the number-of-levels field. Level-dependent variables are listed after the surface variables, and show a "1" in the number-of-levels field. </ul> </ol> <p> <b>Examples</b> <p> Here's a sample descriptor file <code>stat.ctl</code> for station data set <code>ua.reps</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 8<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<br> </code> </ul> <p> Run the <code>stnmap</code> utility: <ul><code>stnmap -i stat.ctl</code></ul> <p> The station map file <code>ua.map</code> is a binary file, which includes the hash table and/or link list information. </body> </html>
