Add 3to4 conversion rule for obselescent magnetics.method

Fixes #116

Author: maarten-ic

imas/ids_convert.py

@@ -428,6 +428,8 @@ def _apply_3to4_conversion(self, old: Element, new: Element) -> None:
         # TODO: define migrations in a separate variable (as with the sign flips)?
         if self.ids_name == "magnetics":
             self._add_rename("bpol_probe", "b_field_pol_probe", reciprocal=False)
+            self._add_rename("method", "ip", reciprocal=False)
+            self.old_to_new.type_change["method"] = _magnetics_method_to_ip
 
         # GH#59: To improve further the conversion of DD3 to DD4, especially the
         # Machine Description part of the IDSs, we would like to add a 3to4 specific
@@ -1335,3 +1337,14 @@ def _equilibrium_boundary_3to4(eq3: IDSToplevel, eq4: IDSToplevel, deepcopy: boo
             node[2].psi = -ts3.boundary_secondary_separatrix.psi  # COCOS change
             node[2].levelset.r = copy(ts3.boundary_secondary_separatrix.outline.r)
             node[2].levelset.z = copy(ts3.boundary_secondary_separatrix.outline.z)
+
+
+def _magnetics_method_to_ip(method: IDSBase, ip: IDSBase) -> None:
+    """Convert obsolescent method(:) to ip(:) in the magnetics IDS."""
+    if not len(method):
+        return
+    ip.resize(len(method))
+    for old_item, new_item in zip(method, ip, strict=True):
+        new_item.method_name.value = old_item.name.value
+        new_item.data.value = old_item.ip.data.value
+        new_item.time.value = old_item.ip.time.value

imas/test/test_ids_convert.py

@@ -450,6 +450,12 @@ def test_3to4_deprecated_magnetics(dd4factory):
     mag.bpol_probe[1].name = "name2"
     mag.bpol_probe[1].voltage.data = [0.1, 0.2, 0.3]
 
+    mag.method.resize(2)
+    for i, method in enumerate(mag.method):
+        method.name = f"name{i}"
+        method.ip.data = [i, 1.0, 2.0]
+        method.ip.time = [i + 1, 2.0, 3.0]
+
     mag4 = convert_ids(mag, None, factory=dd4factory)
     assert len(mag4.b_field_pol_probe) == 2
     assert mag4.b_field_pol_probe[0].name == "identifier1"
@@ -460,14 +466,26 @@ def test_3to4_deprecated_magnetics(dd4factory):
     assert mag4.b_field_pol_probe[1].description == "name2"
     assert array_equal(mag4.b_field_pol_probe[1].voltage.data, [0.1, 0.2, 0.3])
 
+    assert len(mag4.ip) == 2
+    assert mag4.ip[0].method_name == "name0"
+    assert array_equal(mag4.ip[0].data, [0.0, 1.0, 2.0])
+    assert array_equal(mag4.ip[0].time, [1.0, 2.0, 3.0])
+    assert mag4.ip[1].method_name == "name1"
+    assert array_equal(mag4.ip[1].data, [1.0, 1.0, 2.0])
+    assert array_equal(mag4.ip[1].time, [2.0, 2.0, 3.0])
+
     # If both the deprecated and the "correct" quantity exist, we expect only the
     # correct one to be converted to DD4:
     mag.b_field_pol_probe.resize(1)
     mag.b_field_pol_probe[0].name = "test"
+    mag.ip.resize(1)
+    mag.ip[0].method_name = "ip"
 
     mag4 = convert_ids(mag, None, factory=dd4factory)
     assert len(mag4.b_field_pol_probe) == 1
     assert mag4.b_field_pol_probe[0].name == "test"
+    assert len(mag4.ip) == 1
+    assert mag4.ip[0].method_name == "ip"
 
 
 def test_3to4_pulse_schedule():