Prev Next Title Contents

FIRST CONTACT WITH THE PROGRAM.


Entering the program

First insure that the program have been correctly installed from the distribution kit, contact your system manager or your local expert.

You enter the program by typing gifa on your favourite system (don't panic, just type EXIT to get out of it!) . The program should give you a short greeting, the size of the larger data-set, and then respond in the text window with the prompt :

Gifa>

If every thing as been set up correctly, you should also see two spectral windows and a horizontal menu bar showing off. To get the graphics, you should make sure that the environment variable DISPLAY has been correctly set to point on your current terminal (with the command setenv DISPLAY when running UNIX). If no X display is available, Gifa will tell you that no graphic will be available, but will start correctly however.

Principe of operation

There are two ways of issuing commands to Gifa. The first one is to type commands directly in the text window, at the prompt level. Such commands are of two kinds, built-in commands, directly executed by Gifa, and macros, which are command files written in the Gifa command language. From the user level, there is little difference between the two kind of commands.

The other method consists in clicking on a button in the graphic interface. The graphic interface consists in sets of related commands, arranged in vertical button boxes, each such boxes being called by clicking the associated button in the menu bar. Each button box can be opened and closed at will.

The two methods are strictly equivalent, graphic buttons are internally associated to commands (or list of commands). One day, you will eventually learn how to do your own buttons.

Graphic windows can be closed at any time, simply by clicking on their close-box. The 1D window, the 2D contour-plot an the 3D cube window can also be resized. However in certain cases (resizing a 1D in 2D mode for instance, or when a complex drawing has been set, or with the 3D display), the image in the window can be lost for a short time. However the data can never be damaged in any manner.

Entering Parameters

You are now ready to enter your first command. If you hit the About GIFA button in the File button box (the box will show off if you hit the File button in the menu bar), you will get a short introduction.

Entering

Gifa> HELP

at the prompt level will give you the same message. The command HELP is here in uppercase, it can actually be entered also in lowercase, or even in a mixture of upper and lower case letters. In the whole manual, we will use the rule that every built-in Gifa command is given in uppercase. Macros, however have to be typed exactly as defined (this is due to the UNIX file-system), they will always appear in the manual as lower case.

Typing

Gifa> HULP

will give you an error message, since there is no command nor macro named hulp (at least on the distribution kit)!

The HELP command can also be used with a parameter :

Gifa> HELP primer

Some command may require one or several parameters, you will be prompted for such parameters, either in graphic dialogue boxes if the command was entered from a menu, or at the text terminal if the command was typed from it. When entering the prompt level, it is also possible to put the parameter directly after the command on the same line.

For instance, let us try the UNIT command which permits to determine the current unit used on the data-set : PPM, Hertz (as determined form internal parameters) or Index (ranging from 1 to n in the case of a data-set of length n ), or seconds (for time domain data-sets).

Typing

Gifa> UNIT

will prompt you for the unit to use, just typing return will leave the value unchanged.

Typing

Gifa> UNIT H

Will set the current unit to Hertz.

On the other hand, clicking on the Unit button, in the Move menu will pop-up a dialogue box which realises the same thing.

You are now ready to process your first data set.


Prev Next Title Contents