add non-coplanar array test

fftvis/tests/test_compare_matvis.py

@@ -120,3 +120,42 @@ def test_simulate():
 
     # Check that the results are the same
     assert np.allclose(mvis, fvis, atol=1e-5)
+
+
+def test_simulate_non_coplanar():
+    # Simulation parameters
+    ntimes = 10
+    nfreqs = 5
+    nants = 3
+    nsrcs = 20
+
+    # Set random set
+    np.random.seed(42)
+
+    # Define frequency and time range
+    freqs = np.linspace(100e6, 200e6, nfreqs)
+    lsts = np.linspace(0, np.pi, ntimes)
+
+    # Set up the antenna positions
+    antpos = {k: np.array([k * 10, 0, k]) for k in range(nants)}
+
+    # Define a Gaussian beam
+    beam = AnalyticBeam("gaussian", diameter=14.0)
+
+    # Set sky model
+    ra = np.linspace(0.0, 2.0 * np.pi, nsrcs)
+    dec = np.linspace(-0.5 * np.pi, 0.5 * np.pi, nsrcs)
+    sky_model = np.random.uniform(0, 1, size=(nsrcs, 1)) * (freqs[None] / 150e6) ** -2.5
+
+    # Use matvis as a reference
+    mvis = matvis.simulate_vis(
+        antpos, sky_model, ra, dec, freqs, lsts, beams=[beam], precision=2
+    )
+
+    # Use fftvis to simulate visibilities
+    fvis = simulate.simulate_vis(
+        antpos, sky_model, ra, dec, freqs, lsts, beam, precision=2, eps=1e-10
+    )
+
+    # Check that the results are the same
+    assert np.allclose(mvis, fvis, atol=1e-5)