# Using Ferret at PMEL

### Contents:

1. Setting up your account to run Ferret
2. Setting up access to the gridded data base maintained by TMAP
3. Accessing this data base with Ferret
4. Ferret Users Guide

### 1. Setting up your account to run Ferret

- From a MAC or PC:

  1. You must have an X-server application running before Ferret graphics can be displayed. A program such as eXodus (on MACs) or eXceed (on PCs) provides this capability. Please contact a CNSD consultant to learn how to install and start up these programs.

  2. Run the telnet application to log into a Unix workstation on which you have an account. Minimal cost Unix accounts are available to all users on node corona. Please contact CNSD for an account on corona.

  3. Once logged in, set your DISPLAY environment variable to your desk top computer. For example if your MAC is called "NodeName" and your screen id is "0":

     % `setenv DISPLAY NodeName:0`

  4. Set up the paths to run Ferret as described below for Unix workstations.

- On your own Unix workstation or X-terminal:

  Before using Ferret, you must define its environment variables and execution paths. To do that execute the following command from the Unix shell prompt, or place the command in your .cshrc or .login file:

  - On Sun solaris computers:

  % `source /opt/local/ferret/ferret_paths

  - On DEC OSF and Sun sunos computers:

  `
  % `source /usr/local/ferret/ferret_paths`

  - Please NOTE: The source command should be placed before any conditional exit you may have in your .cshrc or .login file. This will prevent problems with the Ferret SPAWN command. Many initialization files around PMEL contain conditional exit lines similar to these:

  # skip remaining setup if not an interactive shell
  if ($?USER == 0 || $?prompt == 0) exit
  # settings for interactive shells

### 2. Setting up access to the gridded data sets

1. The gridded climatological and topographic data sets supported by TMAP are located on five publicly accessible disks. To access the data, the disks must be mounted on the Unix computer from which you run Ferret. These disks are permanently mounted on corona, zippy, and mambo.

   If you are using a different computer, please ask a CNSD consultant to mount the disks on your system (the disks are /home/shiva, /home/shiva2, /home/shiva3, /home/shiva4, /home/shiva5). The data sets are located in the /data directories of these disks.

2. To inform Ferret of the data sets' location on these disks, execute the following command from the Unix shell prompt, or place the command in your .login file:

   - On Sun solaris computers:

       % `source /opt/local/ferret/ferret_shiva_paths

       `
   - On DEC OSF and Sun sunos computers:

       % `source /usr/local/ferret/ferret_shiva_paths`

### 3. Accessing the climatological data base with Ferret

- Using the point-and-click interface:

  Start up Ferret with the command:

  % `ferret -gui`

  The beginners guided tour will get you started using the interface quickly. The basic steps are:

  1. The graphical interface comes up. Choose a data set by using your mouse to select File from the menu bar, then and clicking on the Open Data Set... option.

  2. The interface shows list of data sets available. Double click on one to open it.

  3. To dismiss the Open Data Set menu, click on Dismiss. For information about the available data sets, see the documentation on the data collection.

- Using the command line interface:

  Start up Ferret with the command:

  % `ferret`

  TMAP's online documentation lists the available data sets; each is identified in a table under the heading 'Filename'. Open a data with the Ferret 'SET DATA' command. For example:

  yes? `SET DATA coads_since_1946`

### 4. Ferret Users Guide

- The online Ferret Users Guide provides detailed help on using Ferret. Release notes on recent updates, demos, and further documention for Ferret are also available.

- Further documentation and support for Ferret is available on-line, see the Ferret Web pages.

Dept of Commerce / NOAA / OAR / ERL / PMEL / TMAP |