Udo R. Strauß

CRELEG - A LEGEND-GENERATOR FOR ArcInfo

The CRELEG programm was developed as an extension to ArcInfo's KEY-commands to simplify the generation of the complex legend of the digital Geological Map 1:50.000 of Austria. CRELEG is written in the FORTRAN programming language. The input to CRELEG are simple directives which are describing placement, size, type, text, shade and other parameters of the legend. The output of CRELEG is an AML-procedure, which can be interpreted by ARCPLOT. CRELEG supports several box-types, automatic bracketing of legend- boxes and textalignment.


INTRODUCTION

One of the main targets of the Geological Survey of Austria is the production of printed geological maps in the scale and the pattern of the official topographic map of Austria, which means 213 sheets in the scale 1:50.000. The map production includes geological mapping, basic research, compilation, cartography and prepress assembly. Since 1991 the Geological Survey of Austria has been actively involved in developing a GIS of geological maps (GEOMAP) and in computer-assisted printing of these maps, which was done manually so far. In the development phase it became apparent, that for the preparation of the legends of the geological maps, which contain usually up to 200 boxes and symbols for a sheet, an additional tool beside the ArcInfo KEY-commands (KEYSHADE, KEYBOX, etc.) was necessary. This tool should be able to generate legends in the style of the handcrafted geological map.

GENERATING LEGENDS WITH CRELEG

CRELEG (which stands for CREate LEGend) is written in the FORTRAN 77 programming language and was implemented on MS-DOS and HP/UX. The code is portable, so it should run on every platform with a FORTRAN 77 compiler with no or minor modifications. An ArcInfo user interface simplyfies the design cycle of generating complex legends to geological maps. Currently, CRELEG produces AMLs for ArcInfo 6.1.1. This document is a short introduction for designing and drawing legends with CRELEG and ArcInfo.

The input to CRELEG is an ASCII file (COMMAND.LEG), which contains the directives of the layout of the legend. The syntax of the directives is similar to the ArcInfo KEY-commands. CRELEG generates the output file COMMAND.AML, an AML-procedure, which can be interpreted by ARCPLOT. Additionally, CRELEG writes a log file (Figure 5). "Native" ARCPLOT commands can be embedded in the input file and will be passed through to the AML-procedure.

COMMANDS OF CRELEG

CRELEG understands the following "native" commands:

Commands describing the size, separation and linetype of a rectangular box: Command for defining line patterns in a box: Command for moving and switching drawing modes: Command for defining the angle of a marker: Commands defining the starting and ending points of a bracket: Commands for defining text attributes (height, width, spacing, kerning), maximum characters in a textline and the PostScript option: Commands describing the placement and numbering of the label number in the next box: Command for choosing under several combined box types: Commands describing the shade-,line-,text- and markersymbols of the box: and combinations like

CONCLUSION

CRELEG has been proofen to be a usefull tool to shorten the design- and layout process of generating legends to geological maps. However, to overcome some of its limitations, CRELEGs command driven interface and "grown" syntax need a complete overhaul in the near future. This plans also include the implementation of ArcInfo version 7 features.

ENDNOTES

1. ArcInfo is a registered trademark of Environmental Systems Research, Inc.
2. PostScript is a registered trademark of Adobe Systems, Inc.

REFERENCES

Strauß, Udo and Werner Stöckl. Customising the ArcInfo PostScript Interface for Foreign Languages and User specified Fonts. Proceedings of the Thirteenth Annual Esri User Conference. Redlands: Esri, 1993.


Udo R. Strauß
Geological Survey of Austria
Rasumofskygasse 23
A-1031 Vienna, Austria
Telephone:(43-1) 712-56-74-37
Fax:(43-1) 713-64-57
Email: Udo.Strauss@gbat500.zamg.ac.at