help ARCDLG

ARCDLG <in_cover> <out_dlg_file> {in_point_cover}
       {in_projection_file} {x_shift} {y_shift} {in_header_file}
       {TRANS | NOTRANS}
 
creates a DLG-3 Optional format file from ARC/INFO coverages.
 
 
 
arguments
<in_cover> - the name of the coverage to be converted to DLG format.  It
may contain polygon, line and node features.
 
<out_dlg_file> - the name of the output DLG-3 Optional format file to be
created.
 
{in_point_cover} - an optional coverage containing point features to be
written as zero length, degenerate Line (L) records in the output DLG.
 
{in_projection_file} - a text file containing INPUT projection
parameters to be saved in the DLG header.
 
{x_shift} - a constant value to be added to all coverage x-coordinates
during the conversion to DLG.  {x_shift} overrides any Xshift parameters
found in either {in_projection_file} or <in_cover> projection definition
file.  If neither {x_shift} nor Xshift is specified; the default is 0.
 
{y_shift} - a constant value to be added to all y-coordinates during
conversion to DLG.  The default {y_shift} is determined in the same
manner as the default {x_shift}.
 
{in_header_file} - a file containing information to be written into the
header of the DLG file.  The format of this file is described in the
notes section.
 
{TRANS | NOTRANS} - this operation controls whether or not a coordinate
transformation is performed.  Usually, coordinates are transformed to
preserve accuracy when written to the DLG.  The default is to transform
coordinates in the DLG file.
 
 
 
notes
There are two distribution formats for a DLG file:  the Standard format
and the Optional format.  ARCDLG writes a DLG in the Optional format
only.
 
The internal feature numbers (cover#) are written as the output DLG
feature numbers.
 
Coverage topology is saved in the DLG file using conventions which are
similar to the way topology is stored in a coverage (e.g., polygons are
defined in clockwise loops, islands as counterclockwise loops, each
feature has a unique identification number, negative numbers for lines
indicate reverse directions, and so on).
Here is what is saved in the output DLG.
 
For each <in_cover> polygon:  the polygon's internal number, its label
point location (x,y), the list of arcs which define it, and any
major/minor attribute pairs are all saved in an Area (A) record in the
output DLG.
 
For each <in_cover> arc:  the internal number of the arc, its from-node
and to-node numbers, its coordinates, its left and right polygon
numbers, the set of x,y coordinates which define the line, and any
major/minor attribute pairs are all saved in a Line (L) record in the
output DLG.
 
For each <in_cover> node:  the internal number of the node, its (x,y)
location, a list of arcs beginning or terminating at the node and any
major/minor attribute pairs are all saved in a Node (N) record in the
output DLG.
 
For each {in_point_cover} point feature: its x,y location and any
major/minor attribute pairs are saved in a zero-length Line (L) record.
These are referred to as degenerate lines in a DLG. The feature numbers
for points will be sequential and offset from the last Line (L) record
written to the file. A Node (N) record without the attribute information
will also be created for each degenerate Line record (in accordance with
the DLG format specification).
 
ARCDLG looks for major/minor attribute pairs for lines, polygons and
node features in <in_cover> and for points features in {point_cover}.
 
MAJOR1   MINOR1
MAJOR2   MINOR2
  :        :
MAJORn  MINORn
 
ARCDLG first looks for these items in the feature attribute tables.
If items do not exist in these files, then the appropriate
CODE tables created by DLGARC will be searched.
 
DLG attributes are always integer pairs containing one to six digits.
Items must be paired and defined as numeric items.  Real numbers are
truncated when written to the DLG.  Since 0 is assumed to be a valid
attribute value, -99999 can be used to signify no data.  If -99999 is
encountered for a Major-code or Minor-code item, then the attribute
values are blank in the output DLG, not -99999.
 
Coverage coordinates are not projected by ARCDLG.  The projection
parameters, used only to describe the projection system of the coverage
coordinates, are saved in the output DLG header records.
 
The {in_projection_file} should be in the same format as required by the
PROJECTDEFINE and PROJECT commands.  Projection information will be
taken first from {in_projection_file}, then from <in_cover> projection
definition file.
 
You can use the ARC command PROJECTDEFINE to define projection
parameters for <in_cover>.  If coverage projection has not been defined
and {in_projection_file} is not used, then no projection information
will be written to the output DLG file.
 
Quite often, a constant value is subtracted from coverage coordinates,
especially y-coordinate values in the 3 to 6 million range (UTM).  This
is done to preserve accuracy for single-precision coverages.  This value
is referred to as an x-shift or y-shift and should be added back onto
the coordinates when they are written out to the DLG file.  You can
specify x and y-shift values several different ways.
 
The following is the order of precedence that ARCDLG uses when
determining which values to use.
 
1.Command line options {x_shift} and {y_shift}
2.Xshift and Yshift parameters in{in_projection_file}
3.Xshift and Yshift parameters in <in_cover> (PRJ) file
4.Default value is zero, if not found in any of the above
 
The x and y-shift values are automatically applied to both
{in_header_file} control points and feature coordinates written out to
the DLG file.
 
Header information files are created with your system's text editor and
contain any or all of the keywords listed above.  The default value is
used for each keyword when that keyword is given without specifying a
value.  The order of the keywords in the file is not important.  An
illustration of a header file is shown in the example section.
 
Tics in the <in_cover> are not written to the DLG file.  In order to
preserve tic locations, use the {in_header_file} option and specify the
x,y locations for tics as CONTROLPOINTs in the header file.
 
The xy coordinates for both {in_header_file} control points and coverage
features are automatically scaled to fit the DLG coordinate record
format unless the NOTRANS option is specified.  The transformation
ensures that the accuracy of coordinates is preserved.
 
To create a DLG file which contains only point features, you should
specify an <in_cover> which contains one rectangular polygon defining
the area covered by the points.  Use the name of the point coverage for
the {in_point_cover} argument.
 
Only one DLG category or layer can be saved in a DLG file created by
ARCDLG.  A DLG category is equivalent to a layer in a map.
 
The DLGARC command reads and converts Standard or Optional DLG files
into an ARC/INFO coverage(s).  Refer to the DLGARC command for details.
 
Before creating a DLG file using ARCDLG, each node should be
sequentially numbered using RENODE.  This will ensure that all arc, node
and polygon feature internal numbers are sequential.
 
The following information will be read from the {in_header_file}:
 
        TEXT                character string
        MAPNAME             character string
        CATEGORY            character string
        SOURCEDATE          date, revision date, and revision code
        RESOLUTION          factor real value
        SCALE               denominator integer value
        CONTROLPOINT        SW|NW|NE|SE, Lat,long and x,y
        SECTIONINDICATOR    code and section number
        LARGESTCONTOUR      interval and interval unit
        LARGESTBATHYMETRIC  interval and interval unit
        SMALLESTCONTOUR     interval and interval unit
        SMALLESTBATHYMETRIC interval and interval unit
        HORIZONTALDATUM     datum code
        VERTICALDATUM       datum code
 
example
In this example, a coverage named D1COV is converted into a DLG.  This
coverage is in a UTM projection.  The following is a description of the
coverage coordinate system:
 
 
Coordinate System Description
 
Projection         UTM
Zone                11
Units           METERS    Sheroid       CLARKE1866
Xshift        0.00000     Yshift       3000000.000
 
This projection information will be used by ARCDLG to add projection
parameters to the DLG header records.  This information can be defined
for the coverage using the ARC command PROJECTDEFINE or from an ASCII
file containing the current projection parameters of the coverage.
Coverage coordinates are not projected by ARCDLG.  The projection
parameters, used only to describe the projection system of the coverage
coordinates, are saved in the output DLG header records.
 
Note that a Yshift of 3,000,000 will be added to
coverage coordinates before they are written out to the DLG.
To override an Xshift or Yshift in the projection file, use the
{x_shift} or {y_shift} command line options for ARCDLG.
 
The following header information file named DLGHEAD will be used to
create the appropriate information in the output DLG.
 
Zone should be specified as a ZONE number in the INPUT section of the
projection definition file or as latitude-longitude values in the
PARAMETERS section, but not both.  Only one is written to header records
of the DLG file.
 
 
 
TEXT Example output from ARCDLG
MAPNAME Quad D1
CATEGORY HYDROGRAPHY
SOURCEDATE 1987
RESOLUTION .254
SCALE 100000
CONTROLPOINT  SW   34.250000 -116.750000 523021.47 789710.03
CONTROLPOINT  NW   34.375000 -116.750000 522986.55 803568.26
CONTROLPOINT  NE   34.375000 -116.625000 534477.48 803603.53
CONTROLPOINT  SE   34.250000 -116.625000 534527.64 789745.35
 
 
 
Arc:ARCDLG
Usage: ARCDLG <in_cover> <out_dlg_file> {in_point_cover}
              {in_projection_file} {x_shift} {y_shift} {in_header_file}
              {TRANS | NOTRANS}
 
Arc: ARCDLG D1COV EXAMPLE.DLG # UTM.PRJ # # DLGHEAD ~ NOTRANS
Converting D1COV to DLG file EXAMPLE.DLG
Arc:
 
The following lists part of EXAMPLE.DLG, the output DLG file:
 
 
 
ESRI    DLG DATA  -  CHARACTER FORMAT  -  09-10-87 VERSION
Quad D1                                       1987         100000
Example output from ARCDLG
     3     1    0     2 0.10000000000D+01     4     0     4
-.840260150000000D+08    .330560150000010D+08    .000000000000000D+00
 .000000000000000D+00    .000000000000000D+00    .000000000000000D+00
  000000000000000D+00    .000000000000000D+00    .000000000000000D+00
  000000000000000D+00    .000000000000000D+00    .000000000000000D+00
 .000000000000000D+00    .000000000000000D+00    .000000000000000D+00
  0.10000000000D-01  0.0              0.0               0.0
 SW        34.250000 -116.750000         523021.47   3789710.03
 NW        34.375000 -116.750000         522986.55   3803568.26
 NE        34.375000 -116.625000         534477.48   3803603.53
 SE        34.250000 -116.625000         534527.64   3789745.35
 HYDROGRAPHY            0    60    60 010    16    16 010    74    74
1
 N    1   532268.34  3751394.07            3           0     0
     -6    55   -56
 N    2   520220.85  3759601.41            3           0     0
     -9   -54   -55
 
