Getting started
Here the basic steps to generate a simple picture are described.
It is assumed that gd is properly installed on your system.
1. Prepare a data file
Pickup your favorite text editor and create a data file.
It may look like:
'Fission barriers of Ac isotopes'
X: neutron number
Y: Bf$ / MeV
H: X Y1(droplet),D13 Y2(total),L11
124 6.60 11.11
126 6.57 11.94
128 6.51 10.36
130 6.42 9.18
132 6.32 8.42
H: Y(exp),N6 D+ D- X
8.5 1 1.5 128
W:Ac/ X(129) Y(11) S(20) A(0)
It consists of a header line written above the graph (1st line),
text for the x- and y-axis (X:- and Y:- tags),
two data blocks (starting with the H:-tags)
and an extra text line (W:).
The data blocks themselves comprise a column of x-values as well as
several columns of y-values and y-errors.
Save the data file as, say, first.gd.
2. Start the gd program
Select a shell window and type
gd new
to invoke the latest installed version.
A prompt (Enter Command :) appears indicating that the program is ready
to accept your commands.
3. Read the data
You use the gd command GREAD to read the data file just edited.
Just type
gr first.gd
and the data will be read into memory.
4. Display the data
You use the gd command GDISP to read the data file just edited.
Just type
gd
and the graph will appear on the default graphics screen.
The default representation is determined automatically but can be changed by
specifying additional display parameters.
5. Make a paper copy
You use the gd command GCOPY to create a copy on paper.
There are several options you might choose:
gcopy printerqueue
will generate an immediate picture on the specified PostScript printer queue.
gcopy file.ps
will create a PostScript file with the specified name.
This file can be printed later or included in a text processing program.
6. Leave the session
You use the gd commands GEXIT or EXIT to exit the program.