Merge pull request #2180 from pybamm-team/fix-2d-interpolant

fix shape for 2d interpolant

CHANGELOG.md

@@ -12,6 +12,7 @@
 
 ## Bug fixes
 
+-   Fixed 2D intepolant ([#2180](https://github.com/pybamm-team/PyBaMM/pull/2180))
 -   Fixes a bug where the SPMe always builds even when `build=False` ([#2169](https://github.com/pybamm-team/PyBaMM/pull/2169))
 -   Some events have been removed in the case where they are constant, i.e. can never be reached ([#2158](https://github.com/pybamm-team/PyBaMM/pull/2158))
 -   Raise explicit `NotImplementedError` if trying to call `bool()` on a pybamm Symbol (e.g. in an if statement condition) ([#2141](https://github.com/pybamm-team/PyBaMM/pull/2141))

pybamm/expression_tree/interpolant.py

@@ -55,6 +55,16 @@ def __init__(
             x1, x2 = x
             if y.ndim != 2:
                 raise ValueError("y should be two-dimensional if len(x)=2")
+            if x1.shape[0] != y.shape[1]:
+                raise ValueError(
+                    "len(x1) should equal y=shape[1], "
+                    f"but x1.shape={x1.shape} and y.shape={y.shape}"
+                )
+            if x2 is not None and x2.shape[0] != y.shape[0]:
+                raise ValueError(
+                    "len(x2) should equal y=shape[0], "
+                    f"but x2.shape={x2.shape} and y.shape={y.shape}"
+                )
         else:
             interpolator = interpolator or "cubic spline"
             if isinstance(x, (tuple, list)):
@@ -63,17 +73,12 @@ def __init__(
                 x1 = x
                 x = [x]
             x2 = None
+            if x1.shape[0] != y.shape[0]:
+                raise ValueError(
+                    "len(x1) should equal y=shape[0], "
+                    f"but x1.shape={x1.shape} and y.shape={y.shape}"
+                )
 
-        if x1.shape[0] != y.shape[0]:
-            raise ValueError(
-                "len(x1) should equal y=shape[0], "
-                "but x1.shape={} and y.shape={}".format(x1.shape, y.shape)
-            )
-        if x2 is not None and x2.shape[0] != y.shape[1]:
-            raise ValueError(
-                "len(x2) should equal y=shape[1], "
-                "but x2.shape={} and y.shape={}".format(x2.shape, y.shape)
-            )
         if isinstance(children, pybamm.Symbol):
             children = [children]
         # Either a single x is provided and there is one child

tests/unit/test_expression_tree/test_interpolant.py

@@ -13,7 +13,11 @@ def test_errors(self):
             pybamm.Interpolant(np.ones(10), np.ones(11), pybamm.Symbol("a"))
         with self.assertRaisesRegex(ValueError, "x2"):
             pybamm.Interpolant(
-                (np.ones(10), np.ones(11)), np.ones((10, 12)), pybamm.Symbol("a")
+                (np.ones(12), np.ones(11)), np.ones((10, 12)), pybamm.Symbol("a")
+            )
+        with self.assertRaisesRegex(ValueError, "x1"):
+            pybamm.Interpolant(
+                (np.ones(11), np.ones(10)), np.ones((10, 12)), pybamm.Symbol("a")
             )
         with self.assertRaisesRegex(ValueError, "y should"):
             pybamm.Interpolant(
@@ -29,7 +33,7 @@ def test_errors(self):
             )
         with self.assertRaisesRegex(ValueError, "should equal"):
             pybamm.Interpolant(
-                (np.ones(10), np.ones(12)), np.ones((10, 12)), pybamm.Symbol("a")
+                (np.ones(12), np.ones(10)), np.ones((10, 12)), pybamm.Symbol("a")
             )
         with self.assertRaisesRegex(ValueError, "interpolator should be 'linear'"):
             pybamm.Interpolant(
@@ -77,7 +81,7 @@ def test_interpolation_1_x_2d_y(self):
             )
 
     def test_interpolation_2_x_2d_y(self):
-        x = (np.arange(-5.01, 5.01, 0.05), np.arange(-5.01, 5.01, 0.05))
+        x = (np.arange(-5.01, 5.01, 0.05), np.arange(-5.01, 5.01, 0.01))
         xx, yy = np.meshgrid(x[0], x[1])
         z = np.sin(xx ** 2 + yy ** 2)
         var1 = pybamm.StateVector(slice(0, 1))