adding more nodes

tests/node_tests/freq_split.py

@@ -0,0 +1,35 @@
+import numpy as np
+import pytest
+from tests.node_tests._shared import make_field
+
+
+def test_sum_reconstruction():
+    """Low-pass plus high-pass should reconstruct the original field."""
+    from backend.nodes.freq_split import FrequencySplit
+
+    node = FrequencySplit()
+    field = make_field(shape=(64, 64))
+    low, high = node.process(field, cutoff=0.1)
+    reconstructed = low.data + high.data
+    assert np.allclose(reconstructed, field.data, atol=1e-10)
+
+
+def test_shapes():
+    """Both outputs should have the same shape as the input."""
+    from backend.nodes.freq_split import FrequencySplit
+
+    node = FrequencySplit()
+    field = make_field(shape=(64, 64))
+    low, high = node.process(field, cutoff=0.1)
+    assert low.data.shape == field.data.shape
+    assert high.data.shape == field.data.shape
+
+
+def test_low_pass_smoother():
+    """Low-pass output should have smaller std than the original random data."""
+    from backend.nodes.freq_split import FrequencySplit
+
+    node = FrequencySplit()
+    field = make_field(shape=(64, 64))
+    low, high = node.process(field, cutoff=0.1)
+    assert np.std(low.data) < np.std(field.data)