Polygon resample (#105)

* Fix bug in Polygon.resample

* Add 0.25 micron hypres SQUID in docs

* Bump version to 0.10.1

* Update test_solve.py: Loosen tolerance slightly

docs/notebooks/squids/hypres/xsmall.py

@@ -0,0 +1,89 @@
+import numpy as np
+
+import superscreen as sc
+from superscreen.geometry import box, close_curve
+
+from .layers import hypres_squid_layers
+
+
+def make_squid(with_terminals: bool = True, align_layers: str = "middle"):
+    layers = hypres_squid_layers(align=align_layers)
+    layer_mapping = {
+        "fc": "BE",
+        "fc_center": "BE",
+        "fc_shield": "W1",
+        "pl": "W1",
+        "pl_center": "W1",
+        "pl_shield": "W2",
+        "pl_shield2": "BE",
+    }
+
+    with np.load("squids/hypres/hypres-250nm.npz") as f:
+        polygons = dict(f)
+
+    films = {
+        name: polygons[name]
+        for name in ["fc", "fc_shield", "pl", "pl_shield", "pl_shield2"]
+    }
+    holes = {
+        "pl_center": np.array(
+            [
+                [0.2, -4.75],
+                [0.2, 0.01],
+                [-0.3, 0.01],
+                [-0.3, -4.75],
+                [0.2, -4.75],
+            ]
+        ),
+    }
+    films["pl"] = films["pl"][np.abs(films["pl"][:, 1]) > 0.05]
+    fc = sc.Polygon(points=polygons["fc"])
+    fc = fc.intersection(sc.Polygon(points=box(12)).rotate(30))
+    fc_points = np.roll(fc.points, -1, axis=0)
+    mask = np.ones(len(fc_points), dtype=bool)
+
+    if not with_terminals:
+        mask[4:27] = False
+        holes["fc_center"] = close_curve(fc_points[~mask])
+        holes["fc_center"][[0, -1], :] = (3.9, -3.92)
+        holes["fc_center"][-2, :] = (4.55, -3.5)
+    films["fc"] = close_curve(fc_points[mask])
+
+    fc_shield = sc.Polygon(points=films["fc_shield"])
+    fc_shield = fc_shield.intersection(sc.Polygon(points=box(15)).rotate(30))
+    films["fc_shield"] = fc_shield.points
+
+    films = {name: sc.Polygon(name, points=poly) for name, poly in films.items()}
+    holes = {name: sc.Polygon(name, points=poly) for name, poly in holes.items()}
+
+    terminals = None
+    if with_terminals:
+        terminals = {
+            "fc": [
+                sc.Polygon("source", points=box(2, 0.1))
+                .rotate(30)
+                .translate(dx=5.7, dy=-3.66),
+                sc.Polygon("drain", points=box(2, 0.1))
+                .rotate(30)
+                .translate(dx=3.75, dy=-4.75),
+            ],
+        }
+
+    for name, poly in films.items():
+        poly.layer = layer_mapping[name]
+        if with_terminals and name == "fc":
+            poly.points = poly.resample(401)
+        else:
+            poly.points = poly.resample(201)
+    for name, poly in holes.items():
+        poly.layer = layer_mapping[name]
+        poly.points = poly.resample(201)
+
+    return sc.Device(
+        "hypres_250nm",
+        layers=layers,
+        films=list(films.values()),
+        holes=list(holes.values()),
+        terminals=terminals,
+        length_units="um",
+    )

superscreen/device/polygon.py

@@ -503,9 +503,9 @@ def resample(
             return self.copy()
         points = self.points.copy()
         _, ix = np.unique(points, return_index=True, axis=0)
-        points = points[np.sort(ix)]
+        points = close_curve(points[np.sort(ix)])
         tck, _ = interpolate.splprep(points.T, k=degree, s=smooth)
-        x, y = interpolate.splev(np.linspace(0, 1, num_points - 1), tck)
+        x, y = interpolate.splev(np.linspace(0, 1, num_points), tck)
         points = close_curve(np.stack([x, y], axis=1))
         return Polygon(
             name=self.name,

superscreen/test/test_solve.py

@@ -323,5 +323,5 @@ def test_fluxoid_multi(two_rings):
         assert np.isclose(
             sum(fluxoid).to("Phi_0").m,
             fluxoids[hole_name],
-            atol=3e-6,
+            atol=1e-5,
         )

superscreen/version.py

@@ -1,2 +1,2 @@
-__version_info__ = (0, 10, 0)
+__version_info__ = (0, 10, 1)
 __version__ = ".".join(map(str, __version_info__))