id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
10380	gdal Envelope should allow min_x == max_x and/or min_y == max_y	psmith	jbronn	"When initializing a new {{{django.contrib.gis.gdal.Envelope}}} object, an {{{OGRException}}} is raised if the {{{min_x}}} value is less than or equal to {{{max_x}}}, and if the {{{min_y}}} value is less than or equal to {{{max_y}}}. It would be better if the exception was raised on in the case that {{{min_x}}} was greater than {{{max_x}}} and/or if {{{min_y}}} greater than {{{max_y}}}.

The reason that it is often useful to create an {{{Envelope}}} from a point initially, say from the extent of a {{{django.contrib.gis.geos.Point}}} object, where the {{{min_x}}} and {{{min_y}}} will equal the {{{max_x}}} and {{{max_y}}}, respectively. For example, to find the extent of a set or list of points, it is convenient to iterate over the collection, creating the Envelope initially with the first point from the iteration, then expanding it with each successive point. (Perhaps using the {{{expand_to_include}}} method proposed in #10368.)

Example:
{{{
>>> from django.contrib.gis.geos import Point
>>> from django.contrib.gis.gdal import Envelope
>>> env = None
>>> for pt in [Point(5, 10), Point(-1, 3), Point(9, -2)]:
...     if env is None:
...         env = Envelope(pt.extent)
...     else:
...         env.expand_to_include(pt.extent)
>>> env.tuple
(-1, -2, 9, 10)
}}}

Making this change should have no impact on the semantics of the {{{Envelope}}} class: indeed, the {{{OGREnvelope}}} class in {{{ogr_core.h}}} from which it is derived does not enforce or check for the ordering of the min and max values."		closed	GIS	1.0		fixed	envelope extent gdal		Accepted	1	0	0	0	0	0