m.cogo enhancement request: add declination support

[fgfletcher]

m.cogo converts a sequence of (bearing,distance) pairs into cumulated cartesian (x,y) coordinates beginning from a user provided starting x,y position.

The bearing entry is in the form "N 52:17:04 W", widely used in survey maps.

However, many surveys use magnetic bearings which are rotated from true geographic North by an angle called the Declination - which itself depends on the date and survey location.

Currently when using m.cogo with such data it is first necessary to convert the magnetic bearing by adding(subtracting) the Declination as known for the date and location of the survey.

This is tedious and error prone when a survey could consist of hundreds of bearings, especially as adding a declination can "wrap around" a bearing into a different quadrant, for example: a 15° declination wrapping from N 10 E to N 5 W.

It would be very helpful if one could provide a Declination argument to m.cogo which would be added to each bearing. All that is needed in processing is to add the Declination value to the Azimuth (from input bearing) and handle the special cases of result <0 or >= 360.

Way above my skill level, but I'm hoping somebody might take an interest.

[sbl]

All enhancements should point to 7.8

[neteler]

Ticket retargeted after milestone closed

[neteler]

Ticket retargeted after milestone closed

[neteler]

Ticket retargeted after milestone closed