Issues with Distance conversion from meters to degrees

[anonymous]

Short example :

>>> from django.contrib.gis.measure import Distance
>>> d = Distance(m=1)
>>> print d
1.0 m
>>> print d.degree
57.2957795132

When converting, the following is executed (in measure.py) :

return self.m / self.UNITS[name]

Shouldn't it be :

return self.m * self.UNITS[name]

Or is the degree declaration wrong ?

UNITS = {
    ....
    'degree' : 0.0174532925199,
    ....
}

[jbronn]

Yeah, its a bug. Looks like I put in the wrong conversion factor here.

[jbronn]

The conversion factor was taken from ​EPSG:9122 (GML), and is equal to "= pi/180 radians" -- thus, it's not a valid meter conversion factor. Because the degree distance will vary depending on one's location on the globe, it should probably be removed from this module.

Unless I hear otherwise I'll remove -- questions, comments, ideas?

[jbronn]

(In [7047]) gis: Removed degree conversion from Distance -- should not have been placed here because it is a spherical conversion factor in radians (not meters).

[Simon Litchfield]

Ideally, the Distance object could allow something like this --

degrees = D(km=10).degrees_at(point)

And return the degrees using a spherical projection at that point (a Point object).