converting DLGs

[Wang Song]

	This could be a significant problem because the standard and optional 
formats are quite different. The standard format is a direct character 
representation of the binary archival DLG, explicit topological linkages
are contained only in the line elements; The optional format was designed 
strictly for data interchange. Because topological linkages are explicitly
encoded for all lines, nodes, and area elements, a polygon data structure can
be easily created.

	The file headers are significantly different. The standard format uses
Cartesian coordinate system with the parameters of a transformation from
internal file coordinates to UTMs given in the file header, while the optional
format are using the UTM coordinate system directly for each pair of coordinates
in the DLG files.

	From my understanding, it will be hard to convert the standard format
of DLGs into GRASS without significant change in source code or modification of
 the DLG files significantly.

	USGS folks may be able to provide more helps to convert DLGs from
standard format into the optional format.

--------------------------------------------------------
Song Wang
CAST/NCRI                      Phone: (501) 575-6159
12 Ozark Hall                    Fax: (501) 575-3846
University of Arkansas        E-Mail: wang at cast.uark.edu
Fayetteville, AR 72701
> Hello GRASS Users,
> 
> 	I made the mistake of ordering USGS DLGs in standard format
> instead of optional format.  Is there any way to convert standard
> format DLGs to GRASS files?  I would like to convert them without
> losing the labels. 
> 
> 			Thanks,
> 			John Nugent
>