Is there an envelope class in shapely?

Question

I found the envelope class in Java's JTS library very handy. An envelope holds the minimal and maximal coordinates of a geometry and is also called bounding box sometimes.

I wanted to get the common envelope of a number of shapely points. In JTS you could call expandToInclude to enlarge the envelope point by point.

As JTS was serving as a blueprint to GEOS / shapely, I was expecting something similar in shapely, but could not find it (I am new to the library though). I know it is no rocket science to do it yourself, but I doubt there is no more elegant way to do this. Do you have any idea?

Brazee

Answer 1

No, there's no envelope class in Shapely, which relies on (minx, miny, maxx, maxy) tuples. If you wanted to program in the same JTS style, it would be trivial to write an envelope class wrapping such a tuple.

Another option:

from shapely.geometry import MultiPoint
print MultiPoint(points).bounds

Rawson

Answer 2

To create simple box geometries, there is a box function that returns a rectangular polygon:

from shapely.geometry import box
# box(minx, miny, maxx, maxy, ccw=True)
b = box(2, 30, 5, 33)
b.wkt  # POLYGON ((5 30, 5 33, 2 33, 2 30, 5 30))
b.area  # 9.0

Misplace

Answer 3

For anyone coming here, shapely Polygon has now bounds which I believe is equivalent to JTS envelop. Following is the documentation from official page

from shapely.geometry import Polygon
polygon = Polygon([(0, 0), (1, 1), (1, 0)])
polygon.bounds
(0.0, 0.0, 1.0, 1.0)

Its x-y bounding box is a (minx, miny, maxx, maxy) tuple.

Mezzosoprano

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Answer 4

For anyone new coming here, shapely does have an envelope function (if I understand the original correctly). This requires you to create a MultiPoint object of a minimum of 2 points.

MultiPoint([(0, 0), (1, 1)]).envelope

<POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))>

See here: https://shapely.readthedocs.io/en/latest/manual.html#object.envelope

Returns a representation of the point or smallest rectangular polygon (with sides parallel to the coordinate axes) that contains the object.

Interjacent