Drop the 'invert' keyword for chopping

Author: FranzBangar

examples/advanced/edge_grading.py

@@ -10,7 +10,7 @@
 
 start.chop(0, start_size=0.1)
 start.chop(1, length_ratio=0.5, start_size=0.01, c2c_expansion=1.2, preserve="start_size")
-# start.chop(1, length_ratio=0.5, end_size=0.01, c2c_expansion=1 / 1.2, preserve="end_size")
+start.chop(1, length_ratio=0.5, end_size=0.01, c2c_expansion=1 / 1.2, preserve="end_size")
 start.chop(2, count=1)
 mesh.add(start)
 
@@ -24,6 +24,7 @@
 contract.chop(2, start_size=0.1)
 mesh.add(contract)
 
+# rotate the end block to demonstrate grading propagation on non-aligned blocks
 end = cb.Extrude(contract.get_face("top"), 1)
 end.rotate(np.pi, [0, 0, 1])
 end.chop(2, start_size=0.1)

examples/operation/box.py

@@ -5,12 +5,12 @@
 box = cb.Box([-1, -2, -4], [4, 2, 1])
 
 # direction of corners 0-1
-box.chop(0, start_size=0.02, c2c_expansion=1.2, length_ratio=0.5, invert=False)
-box.chop(0, start_size=0.02, c2c_expansion=1.2, length_ratio=0.5, invert=True)
+box.chop(0, length_ratio=0.5, start_size=0.02, c2c_expansion=1.2)
+box.chop(0, length_ratio=0.5, end_size=0.02, c2c_expansion=1 / 1.2)
 
 # direction of corners 1-2
-box.chop(1, start_size=0.02, c2c_expansion=1.2, length_ratio=0.5, invert=False)
-box.chop(1, start_size=0.02, c2c_expansion=1.2, length_ratio=0.5, invert=True)
+box.chop(1, length_ratio=0.5, start_size=0.02, c2c_expansion=1.2)
+box.chop(1, length_ratio=0.5, end_size=0.02, c2c_expansion=1 / 1.2)
 
 # extrude direction
 box.chop(2, c2c_expansion=1, count=20)

examples/operation/extrude.py

@@ -7,12 +7,12 @@
 extrude = cb.Extrude(base, [0.5, 0.5, 3])
 
 # direction of corners 0-1
-extrude.chop(0, start_size=0.02, c2c_expansion=1.2, length_ratio=0.5, invert=False)
-extrude.chop(0, start_size=0.02, c2c_expansion=1.2, length_ratio=0.5, invert=True)
+extrude.chop(0, length_ratio=0.5, start_size=0.02, c2c_expansion=1.2)
+extrude.chop(0, length_ratio=0.5, end_size=0.02, c2c_expansion=1 / 1.2)
 
 # direction of corners 1-2
-extrude.chop(1, start_size=0.02, c2c_expansion=1.2, length_ratio=0.5, invert=False)
-extrude.chop(1, start_size=0.02, c2c_expansion=1.2, length_ratio=0.5, invert=True)
+extrude.chop(1, length_ratio=0.5, start_size=0.02, c2c_expansion=1.2)
+extrude.chop(1, length_ratio=0.5, end_size=0.02, c2c_expansion=1 / 1.2)
 
 # extrude direction
 extrude.chop(2, c2c_expansion=1, count=20)

examples/operation/wedge.py

@@ -28,7 +28,7 @@
 wedges[-1].set_patch("right", "outlet")
 
 # this will be copied to all next blocks
-wedges[0].chop(1, c2c_expansion=1.2, start_size=0.01, invert=True)
+wedges[0].chop(1, end_size=0.01, c2c_expansion=1 / 1.2)
 
 # Once an entity is added to the mesh,
 # its modifications will not be reflected there;

src/classy_blocks/grading/chop.py

@@ -57,7 +57,6 @@ class Chop:
     count: Optional[int] = None
     end_size: Optional[float] = None
     total_expansion: Optional[float] = None
-    invert: bool = False
     preserve: ChopPreserveType = "c2c_expansion"
 
     def __post_init__(self) -> None:
@@ -92,9 +91,6 @@ def calculate(self, length: float) -> Tuple[int, float]:
             if {"count", "total_expansion", "c2c_expansion", "start_size", "end_size"}.issubset(calculated):
                 self.results["count"] = int(self.results["count"])
 
-                if self.invert:
-                    data["total_expansion"] = 1 / data["total_expansion"]
-
                 return data["count"], data["total_expansion"]
 
             for chop_rel in ChopRelation.get_possible_combinations():
@@ -113,6 +109,17 @@ def calculate(self, length: float) -> Tuple[int, float]:
 
         raise ValueError(f"Could not calculate count and grading for given parameters: {data}")
 
+    def invert(self) -> None:
+        """Modifies this chop so that grading will have an opposite orientation,
+        a.k.a. start -> end and c2c -> 1/c2c."""
+        self.end_size, self.start_size = self.start_size, self.end_size
+
+        if self.c2c_expansion is not None:
+            self.c2c_expansion = 1 / self.c2c_expansion
+
+        if self.total_expansion is not None:
+            self.total_expansion = 1 / self.total_expansion
+
     def copy_preserving(self, inverted: bool = False) -> "Chop":
         """Creates a copy of this Chop with equal count but
         sets other parameters from current data so that
@@ -123,21 +130,10 @@ def copy_preserving(self, inverted: bool = False) -> "Chop":
         for arg in ["total_expansion", "c2c_expansion", "start_size", "end_size"]:
             args[arg] = None
 
-        # TODO: get rid of if-ing
-        if self.preserve == "start_size":
-            if inverted:
-                args["end_size"] = self.results["start_size"]
-            else:
-                args["start_size"] = self.results["start_size"]
-        elif self.preserve == "end_size":
-            if inverted:
-                args["start_size"] = self.results["end_size"]
-            else:
-                args["end_size"] = self.results["end_size"]
-        else:
-            if inverted:
-                args["c2c_expansion"] = 1 / self.results["c2c_expansion"]
-            else:
-                args["c2c_expansion"] = self.results["c2c_expansion"]
-
-        return Chop(**args)
+        args[self.preserve] = self.results[self.preserve]
+        chop = Chop(**args)
+
+        if inverted:
+            chop.invert()
+
+        return chop

src/classy_blocks/items/block.py

@@ -57,7 +57,7 @@ def chop(self, axis: AxisType, chop: Chop) -> None:
             Optionally, this can be the only provided argument;
             in that case c2c_expansion will be set to 1.
         * *start_size:
-            size of the first cell (last if invert==True)
+            size of the first cell
         * *end_size:
             size of the last cell
         * *c2c_expansion:
@@ -66,12 +66,12 @@ def chop(self, axis: AxisType, chop: Chop) -> None:
             ratio between first and last cell size
 
         :Optional keyword arguments:
-        * *invert:
-            reverses grading if True
-        * *take:
-            must be 'min', 'max', or 'avg'; takes minimum or maximum edge
-            length for block size calculation, or average of all edges in given direction.
-            With multigrading only the first 'take' argument is used, others are copied.
+        * *preserve:
+            which of the specified values should be preserved. Must be one of
+            "start_size", "end_size" or "c2c_expansion". The last is default and will produce
+            regular simpleGrading with 3 values for each axis. When start or end size
+            is to be kept, grading will switch to edgeGrading so that cells on each edge
+            will stay consistent start/end size regardless of edge length.
         * *length_ratio:
             in case the block is graded using multiple gradings, specify
             length of current division; see

src/classy_blocks/types.py

@@ -39,7 +39,6 @@ class ChopArgs(TypedDict, total=False):
     count: int
     end_size: float
     total_expansion: float
-    invert: bool
     preserve: ChopPreserveType
 
 

tests/test_grading.py

@@ -1,5 +1,6 @@
 import unittest
 
+import numpy as np
 from parameterized import parameterized
 
 from classy_blocks.grading import relations as rel
@@ -111,25 +112,27 @@ def test_add_division_1(self):
         self.g.length = 2
 
         self.g.add_chop(Chop(length_ratio=0.5, start_size=0.1, c2c_expansion=1.1))
-        self.g.add_chop(Chop(length_ratio=0.5, start_size=0.1, c2c_expansion=1.1, invert=True))
+        self.g.add_chop(Chop(length_ratio=0.5, end_size=0.1, c2c_expansion=1 / 1.1))
 
-        self.assertListEqual(self.g.specification, [[0.5, 8, 1.9487171000000012], [0.5, 8, 0.5131581182307065]])
+        np.testing.assert_almost_equal(
+            self.g.specification, [[0.5, 8, 1.9487171000000012], [0.5, 8, 0.5131581182307065]]
+        )
 
     def test_add_division_2(self):
         """single grading, set c2c_expansion and count"""
         self.g.add_chop(Chop(1, c2c_expansion=1.1, count=10))
-        self.assertListEqual(self.g.specification, [[1, 10, 2.357947691000002]])
+        np.testing.assert_almost_equal(self.g.specification, [[1, 10, 2.357947691000002]])
 
     def test_add_division_3(self):
         """single grading, set count and start_size"""
         self.g.add_chop(Chop(1, count=10, start_size=0.05))
 
-        self.assertListEqual(self.g.specification, [[1, 10, 3.433788027752166]])
+        np.testing.assert_almost_equal(self.g.specification, [[1, 10, 3.433788027752166]])
 
     def test_add_division_inverted(self):
         """Inverted chop, different result"""
-        self.g.add_chop(Chop(0.5, count=10, start_size=0.05, invert=False))
-        self.g.add_chop(Chop(0.5, count=10, start_size=0.05, invert=True))
+        self.g.add_chop(Chop(0.5, count=10, start_size=0.05))
+        self.g.add_chop(Chop(0.5, count=10, end_size=0.05))
 
         self.assertAlmostEqual(self.g.specification[0][2], 1 / self.g.specification[1][2])
 

tests/test_optimize/test_grid.py

@@ -1,5 +1,3 @@
-from typing import Set
-
 import numpy as np
 from parameterized import parameterized
 
@@ -132,7 +130,7 @@ def test_fixed_points(self):
         ]
 
         grid = QuadGrid(positions, indexes)
-        fixed_points: Set[int] = set()
+        fixed_points = set()
 
         for cell in grid.cells:
             fixed_points.update(cell.boundary)