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m.cogo(1)		    GRASS GIS User's Manual		     m.cogo(1)

NAME
       m.cogo  - A simple utility for converting bearing and distance measure-
       ments to	coordinates and	vice versa.
       It assumes a cartesian coordinate system

KEYWORDS
       miscellaneous, distance,	polar

SYNOPSIS
       m.cogo
       m.cogo --help
       m.cogo [-lrc]  [input=name]   [output=name]    [coordinates=east,north]
       [--overwrite]  [--help]	[--verbose]  [--quiet]	[--ui]

   Flags:
       -l
	   Lines are labelled

       -r
	   Convert from	coordinates to bearing and distance

       -c
	   Repeat the starting coordinate at the end to	close a	loop

       --overwrite
	   Allow output	files to overwrite existing files

       --help
	   Print usage summary

       --verbose
	   Verbose module output

       --quiet
	   Quiet module	output

       --ui
	   Force launching GUI dialog

   Parameters:
       input=name
	   Name	of input file
	   Default: -

       output=name
	   Name	for output file
	   Default: -

       coordinates=east,north
	   Starting coordinate pair
	   Default: 0.0,0.0

DESCRIPTION
       m.cogo  converts	data points between bearing and	distance and X,Y coor-
       dinates.	 Only simple bearing/distance or coordinate pairs are handled.
       It assumes a cartesian coordinate system.

       Input  can be entered via standard input	(default) or from the file in-
       put=name. Specifying the	input as "-" also  specifies  standard	input,
       and  is	useful for using the program in	a pipeline.  Output will be to
       standard	output unless a	file name other	than "-"  is  specified.   The
       input  file  must closely adhere	to the following format, where up to a
       10 character label is allowed but not required (see -l flag).

       Example COGO input:
	  P23 N	23:14:12 W 340
	  P24 S	04:18:56 E 230
	  ...

       The first column	may contain a label and	you must use the  -l  flag  so
       the  program  knows.   This is followed by a space, and then either the
       character 'N' or	'S' to indicate	whether	the bearing is relative	to the
       north  or  south	 directions.  After another space, the angle begins in
       degrees,	minutes, and seconds in	 "DDD:MM:SS.SSSS"  format.  Generally,
       the  angle can be of the	form digits + separator	+ digits + separator +
       digits [+ '.' + digits].	 A space follows the angle, and	is  then  fol-
       lowed  by either	the 'E'	or 'W' characters. A space separates the bear-
       ing from	the distance (which should be in appropriate linear units).

       Output of the above input:
	  -134.140211 312.420236 P23
	  -116.832837 83.072345	P24
	  ...

       Unless specified	with the coord option, calculations begin from (0,0).

NOTES
       For those unfamiliar with the notation for bearings:  Picture  yourself
       in  the	center	of  a  circle.	 The first hemispere notation tell you
       whether you should face north or	south.	Then you read  the  angle  and
       either  turn  that  many	 degrees to the	east or	west, depending	on the
       second hemisphere notation.  Finally, you move <distance> units in that
       direction to get	to the next station.

       m.cogo  can be run either non-interactively or interactively.  The pro-
       gram will be run	non-interactively if the user specifies	any  parameter
       or flag.	Use "m.cogo -",	to run the program in a	pipeline.  Without any
       flags or	parameters, m.cogo will	prompt for each	value using the	famil-
       iar GRASS parser	interface.

       This  program  is  very simplistic, and will not	handle deviations from
       the input format	explained above.  Currently, the  program  doesn't  do
       anything	 particularly  useful  with  the output.  However, it is envi-
       sioned that this	program	will be	extended to provide the	capability  to
       generate	vector and/or sites layers.

       Lines may be closed by using the	-c flag	or snapped with	v.clean, lines
       may be converted	to boundaries with v.type, and closed  boundaries  may
       be converted to areas with v.centroids.

EXAMPLES
	  m.cogo -l in=cogo.dat
       Where the cogo.dat input	file looks like:
       # Sample	COGO input file	-- This	defines	an area.
       # <label> <bearing> <distance>
       P001 S 88:44:56 W 6.7195
       P002 N 33:34:15 W 2.25
       P003 N 23:23:50 W 31.4024
       P004 N 05:04:45 W 25.6981
       P005 N 18:07:25 E 22.2439
       P006 N 27:49:50 E 75.7317
       P007 N 22:56:50 E 87.4482
       P008 N 37:45:15 E 37.7835
       P009 N 46:04:30 E 11.5854
       P010 N 90:00:00 E 8.8201
       P011 N 90:00:00 E 164.1128
       P012 S 48:41:12 E 10.1311
       P013 S 00:25:50 W 255.7652
       P014 N 88:03:13 W 98.8567
       P015 S 88:44:56 W 146.2713
       P016 S 88:44:56 W 18.7164

       Round trip:
	  m.cogo -l input=cogo.dat | m.cogo -rl	in="-"

       Import as a vector points map:
	  m.cogo -l input=cogo.dat | v.in.ascii	output=cogo_points x=1 y=2 separator=space

       Shell script to import as a vector line map:
	  m.cogo -l input=cogo.dat | tac | awk '
	      BEGIN { FS=" " ; R=0 }
	      $1~/\d*\.\d*/ { printf(" %.8f %.8f\n", $1, $2) ; ++R }
	      END { printf("L %d\n", R)	}' | tac | \
	      v.in.ascii -n format=standard out=cogo_line

       Convert that lines map into an area:
	  # Add	the -c flag to the above example to close the loop:
	  m.cogo -l -c input=cogo.dat |	...
	      ...
	  v.type input=cogo_line output=cogo_boundary from_type=line to_type=boundary
	  v.centroids input=cogo_boundary output=cogo_area
       If  necessary,  snap  the boundary closed with the v.clean module.  Use
       tool=snap and thresh=0.0001, or some small value.

SEE ALSO
	v.centroids, v.clean, wxGUI vector digitizer, v.in.ascii, v.type

AUTHOR
       Eric G. Miller

SOURCE CODE
       Available at: m.cogo source code	(history)

       Main index | Miscellaneous index	| Topics  index	 |  Keywords  index  |
       Graphical index | Full index

       A(C) 2003-2020 GRASS Development	Team, GRASS GIS	7.8.4 Reference	Manual

GRASS 7.8.4							     m.cogo(1)

NAME | KEYWORDS | SYNOPSIS | DESCRIPTION | NOTES | EXAMPLES | SEE ALSO | AUTHOR | SOURCE CODE

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