Graphic Devices

The characteristics of graphic devices differ from device to device. Therefore, in order to obtain a useful plot, the characteristics of the graphics device in use have to be known in advance. MIDAS can run on various combinations of alpha-numerical terminals, image display systems and graphic devices. How to specify the graphic output device for these possibilities is described below.

If you are using the standard MIDAS configuration (alpha-numerical and graphic terminal together with an image display), the MIDAS start-up procedure MIDAS takes care of the proper assignment. If you want to obtain graphic output on a workstation running under X-Windows you have to issue the command CREATE/GRAPHIC . This command creates a window on the workstation where subsequent plot and overplot commands will write. Up to 4 graphic windows can be created this way. Removal of a window can be done with DELETE/GRAPHIC .

To get plot output on a graphics device (the graphic terminal included), a proper assignment for that device has to be done in advance. Obviously, the assignment depends on the type of device in use and hence may differ from system to system. If your institute mainly uses graphic terminals of brand ``abc'', life would be much simpler if this device were the default one and therefore the assignment to be included in the MIDAS startup procedure. You can ask your local MIDAS support to do so. The assignment to be made is:

• for VAX/VMS systems: ASSIGN AGL_type AGL3DEV;  
• for UNIX systems (C-Shell): setenv AGL3DEV AGL_type;
• for UNIX systems (Bourne-Shell): AGL3DEV=AGL_type.

Changing the assignment from the default device to another one can always been done in the login.prg  file (see Chapter 3). This of course would be useful if a particular device is not assigned by the MIDAS startup procedure but is used regularly. Finally, if you run MIDAS from a stand-alone (non-graphic) terminal, an assignment to the NULL device   or to the postscript device can be made. In the first case only a graphic meta file will be created; in the later case a postscript file. In case of problems consult your local MIDAS support or your system manager.

Table 6.1 contains the most commonly used graphics devices (the AGL_type's) currently supported by MIDAS.

 

Table 6.1: Supported Devices

Device Identification	AGL_type
DEC VT125 terminal	vt125
DEC VT240 terminal	vt125
DEC VT125 terminal with Retrogr.	tkg.vt640
DEC VT100 terminal with Retrogr.	tkg.vt640
CIT101 with CIG 201 card	tkg.cit101
GraphOn GO-250	tkg.vt640
HDS 2200	tkg.hds22
HPGL plotters	hpgl
LN03 plus laser printer	tkg.ln03
Tektronix 4010	tkg.t4010
Tektronix 4014	tkg.t4014
Tektronix 4100 series	tkg.t4100
QMS laser printer	tkg.qms
X-Windows	idi
Apple Laser Writer	pscript
Postscript printers	pscript
Postscript file	pscript
Versatec V-80	raster
Raster devices	raster
Null device	null