diff --git a/.github/workflows/pytest.yml b/.github/workflows/pytest.yml
index 12dfd18d..67fe2f1a 100644
--- a/.github/workflows/pytest.yml
+++ b/.github/workflows/pytest.yml
@@ -9,7 +9,7 @@ jobs:
   pytest:
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10"]
+        python-version: ["3.8", "3.9", "3.10"]
       fail-fast: false
     runs-on: ubuntu-latest
     steps:
@@ -20,14 +20,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install -U \
-          matplotlib \
-          scipy \
-          rectpack \
-          klayout \
-          freetype-py \
-          pytest
-        pip install -e .
+        pip install -e '.[test]'
     - name: Run test
       uses: GabrielBB/xvfb-action@v1
       with:
diff --git a/README.md b/README.md
index f57f4e65..5624c818 100644
--- a/README.md
+++ b/README.md
@@ -23,8 +23,12 @@ If you found PHIDL useful, please consider citing it in (just one!) of your publ
 
 # Installation / requirements
 - Install or upgrade with `pip install -U phidl`
+- Install with `pip install -U phidl[all]` to include optional dependencies (e.g. freetype-py, klayout, rectpack)
 - Python version >=3.6
 
+## Testing
+- Install with test dependencies with `pip install -U phidl[test]` (includes `all` extras as well)
+- Run tests with `pytest` (or `python -m pytest`)
 
 # About PHIDL
 
diff --git a/phidl/device_layout.py b/phidl/device_layout.py
index c1cc6816..f9ef05e1 100644
--- a/phidl/device_layout.py
+++ b/phidl/device_layout.py
@@ -353,9 +353,13 @@ def _line_distances(points, start, end):
     if np.all(start == end):
         return np.linalg.norm(points - start, axis=1)
 
-    vec = end - start
-    cross = np.cross(vec, start - points)
-    return np.divide(abs(cross), np.linalg.norm(vec))
+    line_vec = end - start
+    relative_points = start - points
+    cross = (
+        line_vec[..., 0] * relative_points[..., 1]
+        - line_vec[..., 1] * relative_points[..., 0]
+    )
+    return np.divide(abs(cross), np.linalg.norm(line_vec))
 
 
 def _simplify(points, tolerance=0):
@@ -2728,7 +2732,7 @@ def append(self, path):
             and np.issubdtype(np.array(path).dtype, np.number)
             and (np.shape(path)[1] == 2)
         ):
-            points = np.asfarray(path)
+            points = np.asarray(path, dtype=np.float64)
             nx1, ny1 = points[1] - points[0]
             start_angle = np.arctan2(ny1, nx1) / np.pi * 180
             nx2, ny2 = points[-1] - points[-2]
diff --git a/phidl/geometry.py b/phidl/geometry.py
index 12f077f1..5081a315 100644
--- a/phidl/geometry.py
+++ b/phidl/geometry.py
@@ -943,7 +943,7 @@ def _merge_floating_point_errors(polygons, tol=1e-10):
         Set of corrected polygons.
     """
     if len(polygons) == 0:
-        return np.asfarray([])
+        return np.asarray([], dtype=np.float64)
     stacked_polygons = np.vstack(polygons)
     x = stacked_polygons[:, 0]
     y = stacked_polygons[:, 1]
@@ -1488,7 +1488,7 @@ def _kl_region_to_device(kl_region, layer, name, precision):
     for polygon in kl_region.each():
         polygon = polygon.to_simple_polygon()
         points = _kl_polygon_to_array(polygon)
-        points = np.asfarray(points) * precision
+        points = np.asarray(points, dtype=np.float64) * precision
         D.add_polygon(points, layer=layer)
     return D
 
@@ -2225,7 +2225,7 @@ def import_gds(filename, cellname=None, flatten=False):
                     rotation = 0
                 l = D.add_label(
                     text=label.text,
-                    position=np.asfarray(label.position),
+                    position=np.asarray(label.position, dtype=np.float64),
                     magnification=label.magnification,
                     rotation=rotation * 180 / np.pi,
                     layer=(label.layer, label.texttype),
diff --git a/phidl/path.py b/phidl/path.py
index 1f1aad7e..21c86988 100644
--- a/phidl/path.py
+++ b/phidl/path.py
@@ -1,3 +1,5 @@
+import math
+
 import numpy as np
 
 from phidl.device_layout import CrossSection, Path, _rotate_points
@@ -74,8 +76,8 @@ def _fresnel(R0, s, num_pts, n_iter=8):
     y = np.zeros(num_pts)
 
     for n in range(0, n_iter):
-        x += (-1) ** n * t ** (4 * n + 1) / (np.math.factorial(2 * n) * (4 * n + 1))
-        y += (-1) ** n * t ** (4 * n + 3) / (np.math.factorial(2 * n + 1) * (4 * n + 3))
+        x += (-1) ** n * t ** (4 * n + 1) / (math.factorial(2 * n) * (4 * n + 1))
+        y += (-1) ** n * t ** (4 * n + 3) / (math.factorial(2 * n + 1) * (4 * n + 3))
 
     return np.array([np.sqrt(2) * R0 * x, np.sqrt(2) * R0 * y])
 
@@ -142,7 +144,7 @@ def euler(radius=3, angle=90, p=1.0, use_eff=False, num_pts=720):
         dx = xp - Rp * np.sin(p * alpha / 2)
         dy = yp - Rp * (1 - np.cos(p * alpha / 2))
     else:
-        xbend1 = ybend1 = np.asfarray([])
+        xbend1 = ybend1 = np.array([], dtype=np.float64)
         dx = 0
         dy = 0
 
@@ -293,7 +295,7 @@ def spiral(num_turns=5, gap=1, inner_gap=2, num_pts=10000):
 
 
 def _compute_segments(points):
-    points = np.asfarray(points)
+    points = np.asarray(points, dtype=np.float64)
     normals = np.diff(points, axis=0)
     normals = (normals.T / np.linalg.norm(normals, axis=1)).T
     dx = np.diff(points[:, 0])
diff --git a/requirements.txt b/requirements.txt
index 0769c5c5..a3c81ce2 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,6 @@
-six
+gdspy
+klayout
 numpy
 matplotlib
-gdspy
+rectpack
+six
diff --git a/ruff.toml b/ruff.toml
index 921a9bb3..70f87082 100644
--- a/ruff.toml
+++ b/ruff.toml
@@ -1,7 +1,7 @@
 line-length = 88
 
 [lint]
-select = ["C", "E", "F", "B", "B9", "UP", "I"]
+select = ["C", "E", "F", "B", "B9", "UP", "I", "NPY201"]
 ignore = [
     "E203",
     "E266",
diff --git a/setup.py b/setup.py
index e8de67a5..022d842a 100644
--- a/setup.py
+++ b/setup.py
@@ -10,6 +10,10 @@
     "matplotlib",
 ]
 
+extras_require = {}
+extras_require["all"] = ["freetype-py", "klayout", "rectpack", "scipy"]
+extras_require["test"] = extras_require["all"] + ["pytest"]
+
 # read the contents of your README file
 
 this_directory = path.abspath(path.dirname(__file__))
@@ -24,6 +28,7 @@
     long_description=long_description,
     long_description_content_type="text/markdown",
     install_requires=install_requires,
+    extras_require=extras_require,
     author="Adam McCaughan",
     author_email="amccaugh@gmail.com",
     packages=["phidl"],
diff --git a/tests/test_geometry.py b/tests/test_geometry.py
index 84430b70..63d5613d 100644
--- a/tests/test_geometry.py
+++ b/tests/test_geometry.py
@@ -207,8 +207,10 @@ def test_text():
 
 
 def test_truetype():
-    _ = pytest.importorskip(
-        "phidl.font", reason="Testing of ttf/otf fonts requires the freetype package."
+    pytest.importorskip(
+        "phidl.font",
+        reason="Testing of ttf/otf fonts requires the freetype package.",
+        exc_type=ImportError,
     )
     from os import path
 
@@ -229,8 +231,10 @@ def test_truetype():
 
 @pytest.mark.skipif(sys.version_info < (3, 0), reason="unicode test requires python3")
 def test_unicode():
-    _ = pytest.importorskip(
-        "phidl.font", reason="Testing of ttf/otf fonts requires the freetype package."
+    pytest.importorskip(
+        "phidl.font",
+        reason="Testing of ttf/otf fonts requires the freetype package.",
+        exc_type=ImportError,
     )
     from os import path