GMT Version 3.4 for OS/2 Warp

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Introduction

I have ported the Generic Mapping Tools (GMT) package from Unix to OS/2. GMT is a freely-available package, distributed under the GNU Public License, that produces exceptionally high-quality graphical output; it has been developed by Paul Wessel, currently at the University of Hawaii, and Walter Smith, presently at NOAA. GMT is especially designed for spatial data, and includes ways of displaying information using any one of many map projections. All GMT graphical output is either Postscript or Encapsulated Postscript, and can be printed/viewed on any postscript printer, or printed with a utility such as Ghostscript/GSView. For more details on GMT, refer to the GMT Web Site, which also provides many examples of GMT graphical output. Please refer to the GMT web site for all information on GMT that is not specific to OS/2.

This version of GMT for OS/2 has been built and tested on Warp 4, FixPak 12. No testing has been performed on OS/2 version 2.x of Warp 3, although I expect that the GMT routines, which make no use of PM or the WPS, should work fine on either of these systems.

GMT can be used in a US installation or in an SI (Europe or Asia) installation. The user chooses which system to be used at run-time.

Note: The current version of GMT is 3.4.

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Requirements

System

The present OS/2 version of GMT is required to be installed upon a file system permitting long file names. Under OS/2, of course, this will almost always be HPFS, but it is possible to install GMT on other file systems (such as ext2, used by Linux, or FAT32, used by M$ Windows) for which OS/2 drivers are available.
 

Libraries

Run-time. In addition to the GMT codes, one must also have installed the run-time support for EMX. This plus the remainder of the EMX development system is freely available from Hobbes or LEO. The OS/2 version of GMT has been compiled with EMX version 0.9d (fix level 4), and thus the run-time library corresponding to that version should be used.

Development. In addition to the EMX development system, GMT requires the netCDF libraries, developed by the University Corporation for Atmospheric Research. These are freely available from its ftp site. An OS/2 DLL version of the netCDF library is provided with this distribution. In addition, GMT requires a math library; I have used Sun Microsystem's Freely Distributable Math Library (fdlibm), available from netlib, for the required routines. The necessary routines are made available in the DLL named fdlibm.dll.

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Obtaining the executables

Only the binary executables are made available here, due to the fact that GMT is now extremely portable. Because of its portability, NO changes in the source codes are now required to successfully compile GMT (thanks, Paul and Walter). The basic sources can be obtained using links found on the main GMT home page. From the GMT home page, all the required documentation and associated information can be obtained.

The GMT distribution I am providing includes some supplementary routines, namely the meca routines (which permit earthquake focal mechanisms to be plotted, for example) and the grdraster utility, which permits conversion and extraction of subgrids of certain raster grid formats.

This OS/2 distribution, in contrast to some earlier distributions, is not staticly linked. The executables require, in addition to the EMX libraries, four DLLs. These are (1) the netCDF library (netcdf.dll), (2) Sun's Freely Distributable math library (fdlibm.dll), (3) the GMT Postscript library (psl.dll), and (4) the GMT support library (gmt.dll). All the required libraries, as well as the executables, as provided as part of the basic distribution, gmt3_4.zip. This archives can be obtained here or from Hobbes. Unzipping gmt3_4.zip will provide the following files: 


      ReadMe.txt     :  A brief introduction
      gmt4os2.html   :  What you are reading
      Porting.zip    :  Instructions and files for building the codes
      dll-files.zip  :  The four DLLs required
      exe-files.zip  :  The GMT executables
The DLLs (dll-files.zip) should be placed in a directory in your LIBPATH. The executables (exe-files.zip) should be placed somewhere in your PATH. The files in Porting.zip are only needed if you might wish to rebuild the DLLs and executables yourself.

All other required data files, coastline files, documentation, and associated information should be obtained from links on the GMT web page.

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Environment Variables

The environment variable GMTHOME must to be set for GMT to work properly.  In this respect, the OS/2 distribution is the same as the Unix distribution. GMT will look for required data files in the subdirectory share beneath the main GMT directory specified by GMTHOME. I suggest setting GMTHOME in CONFIG.SYS. In addition, the variable HOME should be set to a directory of the user's choice (it could be the same as GMTHOME); GMT stores default parameters in that directory. Remember to use forward slashes rather than backward slashes to indicate the directories (for example, use SET GMTHOME=d:/GMT rather than SET GMTHOME=d:\GMT).
 

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Idiosyncracies

  1. If you unpack the GMT distribution in a directory g:/GMT, and set the environment variable GMTHOME to g:/GMT, GMT won't find several required files, for unpacking GMT_progs.tar.gz will place them in G:/GMT/GMT3.4/share instead of the expected G:/GMT/share. Moving them to the latter path will solve the problem.
  2. To successfully use, e.g. tcsh, for the examples, one has to rename tcsh.exe to csh.exe and place a copy in a directory /bin on the drive on which the examples reside.
  3. When creating the examples, the TMP or TEMP environment variables are not honored. Instead one has to ensure that a directory /tmp exists in the root of the drive that the examples reside on. If /tmp doesn't exists, the example will fail.

Items 2 and 3 could be solved by using TVFS.

Thanks to Christian Hennecke for pointing out the above features.

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Installation

To install, extract the routines from the archive and set the environment variables as discussed above. Install the executables in the directory /GMT/GMT3.4/bin or in any other location in your PATH. Install the DLLs in a location in your LIBPATH, or modify your LIBPATH to include the directory in which you place the DLLs. Obtain and install documentation as you see fit; note that man pages can be viewed online from the GMT site. If you are unfamiliar with GMT, I strongly suggest getting the nice tutorial, available from the main GMT web site.

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Known Problems

Thus far (24 Dec 2001) there is only one known problem with the port. At least one of the routines (sample1d) seems to have a problem accepting piped output from other routines. This is exemplified when example 3 is run. For example, in example 3 (job03.bash, for instance) the command 

filter1d ship.pg -Fm1 -T$sampr1/$sampr2/1 -E | sample1d -Nsamp.x > samp_ship.pg

fails, yet the executing the commands via temporary files, such as 


filter1d ship.pg -Fm1 -T$sampr1/$sampr2/1 -E > filter1d.tmp
sample1d filter1d.tmp -Nsamp.x > samp_ship.pg
seems to work perfectly. Until such problems are resolved, you might consider using temporary files with sample1d.

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Other Utilities

GMT produces outstanding graphical output. All its output is in the form of either Postscript or Encapsulated Postscript files. Some readily-available utilities are extremely useful for viewing or printing such files. Aladdin Ghostscript provides one the ability to print Postscript files to non-Postscript printers; I recommend it (there is also a Gnu version of ghostscript, which I simply have not used). An outstanding OS/2 utility named GSView, written by Russell Lang, uses Aladdin Ghostscript and provides an OS/2 user the ability to preview Postscript and Encapsulated Postscript files; in addition, GSView can be used as an interface to Ghostscript, permitting Postscript files to be rather easily converted into other formats supported by Ghostscript.

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Help and Bug Reports

This version of GMT is not directly supported by Paul Wessel and Walter Smith, who are the authors of the Unix verison. If you believe you've found a bug, it may well be a bug that applies to the Unix version as well as to the OS/2 version. Be aware that there are two electronic mailing lists available to users. The first, gmtgroup@soest.hawaii.edu, is used primarily to notify users of bug fixes and new versions. The second, gmthelp@soest.hawaii.edu, serves as a users forum for idea exchange and questions about GMT usage. To subscribe to either of these lists, send an e-mail message to listserver@soest.hawaii.edu containing one or both of the commands 
subscribe gmtgroup <your full name, not your e-mail address>
subscribe gmthelp  <your full name, not your e-mail address>
Do not include the angle brackets in the message. Also, if your e-mail client appends a signature file to your outgoing messages, inhibit the sending of the file (or send a blank file).

For questions of bug reports that you believe are specific to the OS/2 version, please send bug reports [e-mail only!] to Allen Cogbill, Los Alamos National Laboratory.

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