2 Installation and System Details

2.1 Getting Started With The GIS Weasel

You have downloaded the GIS Weasel from the GIS Weasel Home Page. The GIS Weasel uses Workstation Arc/Info and its GRID extension, C language executables, and various scripts. The GIS Weasel is capable of running on any platform that Workstation ArcInfo is supported on. The GIS Weasel requires at least version 8.0.2 of Workstation ArcInfo and its GRID extension to run. Desktop ArcInfo is not required. The GIS Weasel does not utilize Desktop ArcInfo, which is the Windows NT-only portion of ArcInfo. 

Unix users can unpack the distribution file by first decompressing it with gzip and then de-archiving it with tar. On a Windows NT platform, standard packages such as WinZip (http://www.winzip.com/), will handle both of these operations. If the user has trouble with WinZip to unpack the GIS Weasel distribution file, they are encouraged to download the Cygwin library (http://www.cygwin.com/) to obtain Windows versions of the gzip and tar (as well as many other useful Unix-like utility programs).

Users are strongly encouraged to carry out the GIS Weasel Problem Sets, once the software has been installed. These problem sets are intended to serve as an introduction to the GIS Weasel.

2.1.1 Unix Users

Unix users have two steps to start the software.

• First, navigate to the GIS Weasel home directory (use the 'cd' command).
• Type: ./weasel

As an alternative to navigating to the GIS Weasel home directory, the user may include the full pathname of the GIS Weasel start up script in lieu of the second step listed above. Another solution is to add the GIS Weasel home directory to the user's PATH environment variable, using the "setenv" or "export" Unix shell commands. For more information, please contact your system administrator.

2.1.2 Windows NT Users

NT users have a few, quick steps to carry out prior to starting the software.

• Use NT Explorer to navigate to the GIS Weasel home directory.

• Right-click on the Weasel-NT!! shortcut (the last file listed in the image shown above), and select the Properties option on the popup menu.

• Once the property sheet, shown above, is presented, bring the Shortcut tab, found at the top of the menu, to the foreground by clicking on the word Shortcut.

• Modify the Target specification, if it is not already correctly specified, to point to the location of the file weasel.bat.
• Modify the Start In specification to point to a convenient directory within your file system, if needed. Make sure that you have write access in the directory that you are specifying! If the GIS Weasel icon is not displayed at the top left corner of the Shortcut page, then press the Change Icon button. This button is found at the lower right of the dialog box.
• If the GIS Weasel icon is displayed, then skip to the second to the last step. A picture of the GIS Weasel icon is shown below.

• Press the Browse button on the Change Icon menu (shown below).

• Navigate to the GIS Weasel home directory and then to the sub-directory src_aml using the menu shown below.

• Change the File Type specification, at the bottom of the newest menu, to All Files.
• Scroll to the right and double click on the filename weasel.bmp.
• Press the Okay button on the first Change Icon menu.
• Press the Okay button on the Weasel-NT!! Properties menu.
• Double-click on the Weasel-NT!! shortcut. You should see the menu shown below.

NT users should feel free to move or copy the Weasel-NT!! shortcut to their desktop, task bar or other convenient location.

2.2 C Language Executables

2.2.1 Unix Users

On Unix platforms, the GIS Weasel's C language executables are compiled with the user's default C compiler, cc. If you have another C compiler that you would rather use, you may substitute the alternate compiler name for "cc" in the GIS Weasel Makefiles, which exist at the paths:

. /weasel/src_c/Makefile (line 17)
. /weasel/src_c/weasel_mms_dmi/Makefile (line 13)

The C language code is compiled the first time that the GIS Weasel is run. If the GIS Weasel is being centrally installed in a directory that users do not have write access to, then the system administrator should start the GIS Weasel once after installation to insure that the C code has been successfully compiled. Once the C code is compiled, any user should be able run the C language executables.

2.2.2 Windows NT Users

On Windows-NT platforms, the GIS Weasel's C language routines are pre-compiled. There are no modifications that the user can make to these files. Please contact the corresponding author (rviger@usgs.gov) directly if any problems are experienced with the C language executables.

2.2.3 Note

Note that because the GIS Weasel uses compiled code, a single installation should not be shared across different platforms. For example, the same installation of the GIS Weasel will not function properly if used for both Solaris and HP-UX operating systems.

2.3 Start-up Command for ArcInfo

Both the GIS Weasel start-up script for Unix, weasel, and for Windows-NT, weasel.bat, assume that ArcInfo is invoked with the word "arc". If this is not the case, then you must change the 8th line of the scripts so that the ARC_COMMAND is set to whatever it is your system uses to invoke ArcInfo.

2.4 Inaccessible, Busy, or Deadlocked Interfaces

In general, if a user sees a menu on the screen, then they expect to be able to interact with that menu. This is not always the case. The GIS Weasel may temporarily disable portions of the GUI in order to eliminate access to functionality that is currently inappropriate. A menu’s “accessibility” is indicated when the user moves the mouse cursor over a menu and the traditional arrowhead icon changes to a wristwatch icon. If the GIS Weasel is actively executing a process, then the user must wait for this process to be completed before any GIS Weasel menus are able to respond to user interaction. If the GIS Weasel is waiting for the user to input information via the map display, then all menus are typically inaccessible. In this case, the mouse cursor will be followed by a cross-hair while in the map display area. If the GIS Weasel is waiting for the user’s interaction with a specific menu, then all other menus can be rendered inaccessible. This menu can become buried by other graphic displays and the user might have to dig through the clutter of windows on their desktop.

If a user is afraid that the GIS Weasel has become deadlocked, they should carefully verify that: 1) no processing is ongoing, 2) that no input is being waited for via the map display, and that 3) all menus are inaccessible. Terminating the GIS Weasel with anything other than the Quit button on the Pan/Zoom menu is strongly discouraged and should be considered only as a last resort.

2.5 The GIS Weasel and the Operating System

At several points, the GIS Weasel will make calls to the operating system, known as system calls. This allows the GIS Weasel to make use of the operating system, as well as ArcInfo. When these calls are made, they are executed within a newly invoked shell. This shell will disappear as soon as the process is completed. The user’s (or operating system’s) default shell settings will be in evidence during the existence of the temporary shell.  Unusual shell settings can occasionally cause problems for the GIS Weasel and ArcInfo.

In general, settings associated with the creation of a new shell should append new information to pre-existing environment variables; these settings should never re-initialize environment variables. This causes additions that ArcInfo has made to the environment variables to be erased, and typically causes ArcInfo system calls to specific programs to fail. Here is an example of an error message that resulted from an environment variable that re-initialized:

ld.so.1: /data2/esri/arcinfo/arcexe80/bin/generate: fatal: libaiaml.so: open failed: No such file or directory

Under Unix, ArcInfo system calls use the C shell. The C shell is configured according to the file, .cshrc, which is found in the user’s home directory. If the user has no .cshrc file in their home directory, then a system default .cshrc file is used. .cshrc lines like the ones shown below have all caused problems for the execution of the GIS Weasel.

if ($?prompt == 0) exit
cd
alias cd `cd {};\!`pwd`:'

Aliases of basic operating system commands, start-up commands that change the current directory setting, and re-initialization of environment variables should avoided.

2.6 Reporting Bugs

The GIS Weasel, obviously, is still under development. The authors value any feedback that will help in the design of a better set of tools. Please report any bugs, including the watch files (“test.wat” and/or “param.wat”) and a description of the hardware and operating system you are working with.

2.7 Updates

If you are interested in updates, sign up for the GIS Weasel Mailing List through the GIS Weasel Home page. Users are encouraged to periodically check the GIS Weasel Home Page to see if updates have been made.

U.S. Department of the Interior | U.S. Geological Survey
URL: http://wwwbrr.cr.usgs.gov/projects/SW_MoWS/software/weasel_s/install_instruct.shtml
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Page Last Modified: October 20, 2006