Merge pull request #643 from jdegenstein/hexloc_majradius

Add major_radius bool to HexLocations and rename apothem parameter to radius

examples/heat_exchanger.py

@@ -48,7 +48,7 @@
     tube_locations = [
         l
         for l in HexLocations(
-            apothem=(tube_diameter + tube_spacing) / 2,
+            radius=(tube_diameter + tube_spacing) / 2,
             x_count=exchanger_diameter // tube_diameter,
             y_count=exchanger_diameter // tube_diameter,
         )

examples/heat_exchanger_algebra.py

@@ -19,7 +19,7 @@
 tube_locations = [
     l
     for l in HexLocations(
-        apothem=(tube_diameter + tube_spacing) / 2,
+        radius=(tube_diameter + tube_spacing) / 2,
         x_count=exchanger_diameter // tube_diameter,
         y_count=exchanger_diameter // tube_diameter,
     )

src/build123d/build_common.py

@@ -49,7 +49,7 @@
 import functools
 from abc import ABC, abstractmethod
 from itertools import product
-from math import sqrt
+from math import sqrt, cos, pi
 from typing import Any, Callable, Iterable, Optional, Union, TypeVar
 from typing_extensions import Self, ParamSpec, Concatenate
 
@@ -860,20 +860,30 @@ class HexLocations(LocationList):
     """Location Context: Hex Array
 
     Creates a context of hexagon array of locations for Part or Sketch. When creating
-    hex locations for an array of circles, set `apothem` to the radius of the circle
+    hex locations for an array of circles, set `radius` to the radius of the circle
     plus one half the spacing between the circles.
 
     Args:
-        apothem (float): radius of the inscribed circle
-        xCount (int): number of points ( > 0 )
-        yCount (int): number of points ( > 0 )
+        radius (float): distance from origin to vertices (major), or
+            optionally from the origin to side (minor or apothem)
+            with major_radius = False
+        x_count (int): number of points ( > 0 )
+        y_count (int): number of points ( > 0 )
+        major_radius (bool): If True the radius is the major radius, else the
+            radius is the minor radius (also known as inscribed radius).
+            Defaults to False.
         align (Union[Align, tuple[Align, Align]], optional): align min, center, or max of object.
             Defaults to (Align.CENTER, Align.CENTER).
 
     Attributes:
-        apothem (float): radius of the inscribed circle
-        xCount (int): number of points ( > 0 )
-        yCount (int): number of points ( > 0 )
+        radius (float): distance from origin to vertices (major), or
+            optionally from the origin to side (minor or apothem)
+            with major_radius = False
+        apothem (float): radius of the inscribed circle, also known as minor radius
+        x_count (int): number of points ( > 0 )
+        y_count (int): number of points ( > 0 )
+        major_radius (bool): If True the radius is the major radius, else the
+            radius is the minor radius (also known as inscribed radius).
         align (Union[Align, tuple[Align, Align]]): align min, center, or max of object.
         diagonal (float): major radius
         local_locations (list{Location}): locations relative to workplane
@@ -884,23 +894,32 @@ class HexLocations(LocationList):
 
     def __init__(
         self,
-        apothem: float,
+        radius: float,
         x_count: int,
         y_count: int,
+        major_radius: bool = False,
         align: Union[Align, tuple[Align, Align]] = (Align.CENTER, Align.CENTER),
     ):
         # pylint: disable=too-many-locals
 
-        diagonal = 4 * apothem / sqrt(3)
+        if major_radius:
+            diagonal = 2 * radius
+            apothem = radius * cos(pi / 6)
+        else:
+            diagonal = 4 * radius / sqrt(3)
+            apothem = radius
+
         x_spacing = 3 * diagonal / 4
         y_spacing = diagonal * sqrt(3) / 2
         if x_spacing <= 0 or y_spacing <= 0 or x_count < 1 or y_count < 1:
             raise ValueError("Spacing and count must be > 0 ")
 
+        self.radius = radius
         self.apothem = apothem
         self.diagonal = diagonal
         self.x_count = x_count
         self.y_count = y_count
+        self.major_radius = major_radius
         self.align = tuplify(align, 2)
 
         # Generate the raw coordinates relative to bottom left point

tests/test_build_common.py

@@ -320,6 +320,16 @@ def test_hex_no_centering(self):
         for position in positions:
             self.assertTrue(position.X <= 0 and position.Y <= 0)
 
+    def test_hex_major_radius(self):
+        hex = RegularPolygon(1, 6)
+        with BuildSketch() as s:
+            with HexLocations(1, 3, 3, major_radius=True) as hloc:
+                add(hex)
+        self.assertAlmostEqual(s.sketch.face().area, hex.area * 9, 7)
+        self.assertAlmostEqual(hloc.radius, 1, 7)
+        self.assertAlmostEqual(hloc.diagonal, 2, 7)
+        self.assertAlmostEqual(hloc.apothem, 3**0.5 / 2, 7)
+
     def test_centering(self):
         with BuildSketch():
             with GridLocations(4, 4, 2, 2, align=(Align.CENTER, Align.CENTER)) as l: