From 023ffa3eb1e8917955c1bd95ca9d2119ff52658f Mon Sep 17 00:00:00 2001
From: josidd <joseph.siddons@noc.ac.uk>
Date: Tue, 8 Oct 2024 09:47:07 +0100
Subject: [PATCH] feat(1d_neighbours): add option to test sortedness
- raise error if not sorted.
- warn if not testing sortedness.
---
GeoSpatialTools/neighbours.py | 34 +++++++++++++++++++++++++++++++++-
test/test_neighbours.py | 9 ++++++++-
2 files changed, 41 insertions(+), 2 deletions(-)
diff --git a/GeoSpatialTools/neighbours.py b/GeoSpatialTools/neighbours.py
index 82c562e..965fca6 100644
--- a/GeoSpatialTools/neighbours.py
+++ b/GeoSpatialTools/neighbours.py
@@ -4,11 +4,20 @@ from numpy import argmin
from bisect import bisect
from typing import TypeVar
from datetime import date, datetime
+from warnings import warn
Numeric = TypeVar("Numeric", int, float, datetime, date)
+class SortedWarning(Warning):
+ pass
+
+
+class SortedError(Exception):
+ pass
+
+
def _find_nearest(vals: list[Numeric], test: Numeric) -> int:
i = bisect(vals, test) # Position that test would be inserted
@@ -22,7 +31,11 @@ def _find_nearest(vals: list[Numeric], test: Numeric) -> int:
return test_idx[argmin([abs(test - vals[j]) for j in test_idx])]
-def find_nearest(vals: list[Numeric], test: list[Numeric]) -> list[int]:
+def find_nearest(
+ vals: list[Numeric],
+ test: list[Numeric] | Numeric,
+ check_sorted: bool = True,
+) -> list[int] | int:
"""
Find the nearest value in a list of values for each test value.
@@ -36,10 +49,29 @@ def find_nearest(vals: list[Numeric], test: list[Numeric]) -> list[int]:
checked, nor is the list sorted.
test : list[Numeric]
List of query values
+ check_sorted : bool
+ Optionally check that the input vals is sorted. Raises an error if set
+ to True (default), displays a warning if set to False.
Returns
-------
A list containing the index of the nearest neighbour in vals for each value
in test.
"""
+ if check_sorted:
+ s = _check_sorted(vals)
+ if not s:
+ raise SortedError("Input values are not sorted")
+ else:
+ warn("Not checking sortedness of data", SortedWarning)
+
+ if not isinstance(test, list):
+ return _find_nearest(vals, test)
+
return [_find_nearest(vals, t) for t in test]
+
+
+def _check_sorted(vals: list[Numeric]) -> bool:
+ return all(vals[i + 1] >= vals[i] for i in range(len(vals) - 1)) or all(
+ vals[i + 1] <= vals[i] for i in range(len(vals) - 1)
+ )
diff --git a/test/test_neighbours.py b/test/test_neighbours.py
index fd2a6e2..e9fdbc7 100644
--- a/test/test_neighbours.py
+++ b/test/test_neighbours.py
@@ -3,6 +3,7 @@ from numpy import argmin
from random import choice, sample
from datetime import datetime, timedelta
from GeoSpatialTools import find_nearest
+from GeoSpatialTools.neighbours import SortedError, SortedWarning
class TestFindNearest(unittest.TestCase):
@@ -27,7 +28,13 @@ class TestFindNearest(unittest.TestCase):
assert ours == greedy
- pass
+ def test_sorted_warn(self):
+ with self.assertWarns(SortedWarning):
+ find_nearest([1., 2., 3.], 2.3, check_sorted=False)
+
+ def test_sorted_error(self):
+ with self.assertRaises(SortedError):
+ find_nearest([3., 1., 2.], 2.3)
if __name__ == "__main__":
--
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