Merge pull request #52 from GNS-Science/feature/51-backarc-fun

Feature/51 backarc fun

.bumpversion.cfg

@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 0.8.1
+current_version = 0.8.2
 commit = True
 tag = True
 

CHANGELOG.md

@@ -5,6 +5,9 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.8.2] - 2024-09-21
+### Added
+ - within_polygon helper function
 
 ## [0.8.1] - 2024-07-03
 bumpversion required to trigger updated build pipeline

nzshm_common/__init__.py

@@ -1,6 +1,6 @@
 __author__ = "GNS Science"
 __email__ = '[email protected]'
-__version__ = '0.8.1'
+__version__ = '0.8.2'
 
 from .location import location
 

nzshm_common/geometry/geometry.py

@@ -1,9 +1,13 @@
 """Simple polygon builder methods."""
 
 import math
+from typing import TYPE_CHECKING, Iterable, List
 
 import shapely.wkt
-from shapely.geometry import Polygon
+from shapely.geometry import Point, Polygon
+
+if TYPE_CHECKING:  # pragma: no cover
+    from nzshm_common import CodedLocation
 
 
 def create_hexagon(edge: float, x: float, y: float):
@@ -52,3 +56,23 @@ def backarc_polygon() -> Polygon:
     """
 
     return shapely.wkt.loads(BA_POLYGON_WKT)
+
+
+# TODO: consider if this function and any of the geometry operation functions belong in thier own repo. This
+# would remove dependencies from what is supposed to be a pure python library and allow us to consolodate
+# all geometry operations into one lib (including those in solvis and eq-fault-geom)
+def within_polygon(locations: Iterable['CodedLocation'], polygon: Polygon) -> List[bool]:
+    """
+    Check if points are within a given polygon.
+    Uses shapley.geometry.Polygon.contains() which will be false for points on the polygon boundary.
+
+    Args:
+        locations: the points to check
+        polygon: the polygon
+
+    Returns:
+        A list of boolian values True if the point is within the polygon and False if not
+    """
+
+    points = [Point(loc.lon, loc.lat) for loc in locations]
+    return [polygon.contains(point) for point in points]

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "nzshm-common"
-version = "0.8.1"
+version = "0.8.2"
 homepage = "https://github.com/GNS-Science/nzshm-common-py"
 description = "A small pure python library for shared NZ NSHM data like locations."
 authors = ["GNS Science <[email protected]>"]

tests/test_geometry.py

@@ -1,12 +1,17 @@
 import math
 import unittest
 
+from nzshm_common import CodedLocation
 from nzshm_common.grids import RegionGrid, load_grid
 
 try:
     import shapely  # noqa
 
-    from nzshm_common.geometry.geometry import create_hexagon, create_square_tile  # these require shapely
+    from nzshm_common.geometry.geometry import (  # these require shapely
+        create_hexagon,
+        create_square_tile,
+        within_polygon,
+    )
 
     HAVE_SHAPELY = True
 except ImportError:
@@ -106,3 +111,21 @@ def test_adjacent_hexagons_pt1(self):
         print('cell spacing', cells[0].distance(cells[1]))
 
         self.assertAlmostEqual(cells[0].distance(cells[1]), 0.0)
+
+
+@unittest.skipUnless(HAVE_SHAPELY, "Test requires optional shapely module.")
+def test_within_polygon():
+    coords = ((0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (1.0, 0.0), (0.0, 0.0))
+    polygon = shapely.geometry.Polygon(coords)
+    locations = [
+        CodedLocation(0, 0, 0.001),
+        CodedLocation(2, 2, 0.001),
+        CodedLocation(0.5, 2, 0.001),
+        CodedLocation(0.5, 0.5, 0.001),
+    ]
+    within_expected = [False, False, False, True]
+
+    within = within_polygon(locations, polygon)
+
+    assert len(within) == len(within_expected)
+    assert within == within_expected