Fix division by zero bug for cubes with only one line

seismic_zfp/utils.py

@@ -53,7 +53,11 @@ def __init__(self, traces_ref):
 
     @staticmethod
     def get_range(ids):
-        return min(ids), max(ids), (max(ids) - min(ids)) // (len(ids) - 1)
+        if len(ids)>1:
+            step = (max(ids) - min(ids)) // (len(ids) - 1)
+        else:
+            step = 0 # For 3D cubes with only one inline or crossline
+        return min(ids), max(ids), step
 
     def __repr__(self):
         return f'IL:[{self.min_il},{self.max_il},{self.il_step}] -- XL:[{self.min_xl},{self.max_xl},{self.xl_step}]'

tests/test_utils.py

@@ -122,3 +122,8 @@ def test_python_int():
     assert 1 == python_int(np.int8(1))
     with pytest.raises(TypeError):
         python_int("1")
+
+
+def test_get_range():
+    assert InferredGeometry3d.get_range([0,1,2]) == (0, 2, 1)
+    assert InferredGeometry3d.get_range([0]) == (0, 0, 0)