DLGWRIT -- Write DLG to Text File

Writes vector data from a PCIDSK vector segment to a USGS (United States Geological Survey) Optional DLG (Digital Line Graph) Distribution Format text file for a 1:100000-Scale map.

Note: DLGWRIT does NOT write Standard DLG Distribution Format or Optional 1:2000000-Scale DLG Distribution Format text files.

See Also: DLGREAD, MIDLG

PARAMETERS

DLGWRIT is controlled by the following global parameters: 

Name     Prompt                                  Count     Type
FILE     Database File Name                      1-64      Char
DBVS     Database Vector Segment                 1         Int
TFILE    Text File Name                          1-64      Char

FILE

Specifies the name of the PCIDSK image file containing the vector segment (type 116). 

 EASI>FILE="filespec"

DBVS

Specifies the number of the database vector segment (type 116) which contains vector data to be written to the DLG format text file. 

 EASI>DBVS=i

TFILE

  Valid Values:   <filename, max. 64 characters>
  Default:        <none>
Specifies the name for the new DLG format text file to be created. 

 EASI>TFILE="filename"

DETAILS

DLGWRIT writes vector data from a vector segment (DBVS) on a PCIDSK file (FILE) to a new USGS (United States Geological Survey) Optional DLG (Digital Line Graph) Distribution Text File Format (TFILE) for 1:100000-Scale. The Standard DLG Distribution Format and the 1:2000000-Scale (Albers equal-area conic projection metres) Optional DLG Distribution Format text files are NOT supported.

The DLG file created by this program contains Level 1 ("spaghetti" vector) and Level 2 (attribute code) information, but does NOT have Level 3 (topology) information. The current PCIDSK vector segment format is not able to store topology. However, the PCIDSK vector segment can store one attribute value for each line structure, which combines the Major and Minor attribute code associated with the DLG line. The Minor code is the last four digits, and the Major code is the remaining high-order digits of the numeric attribute value. For example, if a line structure has an attribute value of 500200, then the Major code is 050 and the Minor code is 0200 (this is the code for a shoreline). These codes are saved in the output DLG text file for each line. However, only ONE attribute code (major and minor) can be saved per DLG line.

The output map scale is always set to 1:100000.

EXAMPLE

Write the transportation vector data stored in vector segment 25 from PCIDSK file irvine.pix to a new DLG format text file. (This segment was originally created by the MIDLG program, which reads USGS DLG vector data from tape). 

 EASI>FILE="/pci/demo/irvine.pix"
 EASI>DBVS=25
 EASI>TFILE="irvine.dlg"
 EASI>RUN DLGWRIT
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