Fix rotation of hexagons in block diagrams

armi/reactor/grids/hexagonal.py

@@ -160,6 +160,16 @@ def pitch(self) -> float:
         """
         return self._unitSteps[1][1]
 
+    @property
+    def cornersUp(self) -> bool:
+        """
+        Check whether the hexagonal grid is "corners up" or "flats up".
+
+        See the armi.reactor.grids.HexGrid class documentation for an
+        illustration of the two types of grid indexing.
+        """
+        return self._unitSteps[0][1] != 0.0
+
     @staticmethod
     def indicesToRingPos(i: int, j: int) -> Tuple[int, int]:
         """

armi/utils/plotting.py

@@ -1168,6 +1168,11 @@ def _makeBlockPinPatches(block, cold):
 
     sortedComps = sorted(block, reverse=True)
 
+    if isinstance(block.spatialGrid, grids.HexGrid):
+        hexRotation = 0 if block.spatialGrid.cornersUp else 30
+    else:
+        hexRotation = 0
+
     derivedComponents = block.getComponentsOfShape(DerivedShape)
     if len(derivedComponents) == 1:
         derivedComponent = derivedComponents[0]
@@ -1185,7 +1190,10 @@ def _makeBlockPinPatches(block, cold):
         x, y, _ = location.getLocalCoordinates()
         if isinstance(comp, Hexagon):
             derivedPatch = matplotlib.patches.RegularPolygon(
-                (x, y), 6, radius=largestPitch / math.sqrt(3)
+                (x, y),
+                6,
+                radius=largestPitch / math.sqrt(3),
+                orientation=(hexRotation - 30.0) * (2.0 * math.pi) / 360.0,
             )
         elif isinstance(comp, Square):
             derivedPatch = matplotlib.patches.Rectangle(
@@ -1212,7 +1220,9 @@ def _makeBlockPinPatches(block, cold):
 
             # goes through each location
             # want to place a patch at that location
-            blockPatches = _makeComponentPatch(component, (x, y), cold)
+            blockPatches = _makeComponentPatch(
+                component, (x, y), cold, hexRotation=hexRotation
+            )
             for element in blockPatches:
                 patches.append(element)
 
@@ -1227,7 +1237,7 @@ def _makeBlockPinPatches(block, cold):
     return patches, data, names
 
 
-def _makeComponentPatch(component, position, cold):
+def _makeComponentPatch(component, position, cold, hexRotation=30):
     """Makes a component shaped patch to later be used for making block diagrams.
 
     Parameters
@@ -1240,14 +1250,18 @@ def _makeComponentPatch(component, position, cold):
         cold: boolean
             True if looking for dimension at cold temps
 
+        hexRotation: float, optional
+            Amount of counterclockwise rotation (in degrees) for a hexagon component patch. 0 degrees
+            corresponds to a hexagon with its corner pointing up.
+
     Return
     ------
         blockPatch: List
             A list of Patch objects that together represent a component in the diagram.
 
     Notes
     -----
-    Currently accepts components of shape DerivedShape, Helix, Circle, or Square
+    Currently accepts components of shape DerivedShape, Helix, Circle, Hexagon, or Square
     """
     x = position[0]
     y = position[1]
@@ -1283,10 +1297,10 @@ def _makeComponentPatch(component, position, cold):
     elif isinstance(component, Hexagon):
         if component.getDimension("ip", cold=cold) != 0:
             innerPoints = numpy.array(
-                hexagon.corners(30) * component.getDimension("ip", cold=cold)
+                hexagon.corners(hexRotation) * component.getDimension("ip", cold=cold)
             )
             outerPoints = numpy.array(
-                hexagon.corners(30) * component.getDimension("op", cold=cold)
+                hexagon.corners(hexRotation) * component.getDimension("op", cold=cold)
             )
             blockPatch = []
             for n in range(6):
@@ -1301,7 +1315,10 @@ def _makeComponentPatch(component, position, cold):
         else:
             # Just make it a hexagon...
             blockPatch = matplotlib.patches.RegularPolygon(
-                (x, y), 6, radius=component.getDimension("op", cold=cold) / math.sqrt(3)
+                (x, y),
+                6,
+                radius=component.getDimension("op", cold=cold) / math.sqrt(3),
+                orientation=(hexRotation - 30.0) * (2.0 * math.pi) / 360.0,
             )
 
     elif isinstance(component, Rectangle):