From b713264d52c81b06addc337a357deda571857d2c Mon Sep 17 00:00:00 2001
From: Richard <richardhayes777@gmail.com>
Date: Mon, 13 Feb 2023 10:09:44 +0000
Subject: [PATCH] fix handling deeper attributes in interpolation

---
 autofit/mapper/model_object.py    |  2 +-
 test_autofit/test_interpolator.py | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/autofit/mapper/model_object.py b/autofit/mapper/model_object.py
index 19b01e116..efd7806cb 100644
--- a/autofit/mapper/model_object.py
+++ b/autofit/mapper/model_object.py
@@ -48,7 +48,7 @@ def replacing_for_path(self, path: Tuple[str, ...], value) -> "ModelObject":
         new = copy.deepcopy(self)
         obj = new
         for key in path[:-1]:
-            obj = getattr(new, key)
+            obj = getattr(obj, key)
 
         setattr(obj, path[-1], value)
         return new
diff --git a/test_autofit/test_interpolator.py b/test_autofit/test_interpolator.py
index 2e0de50bd..94766e0bd 100644
--- a/test_autofit/test_interpolator.py
+++ b/test_autofit/test_interpolator.py
@@ -53,3 +53,24 @@ def test_alternate_attribute(time_series, sigma):
     assert result.gaussian.sigma == sigma
     assert result.t == -sigma
     assert result.gaussian.normalization == -sigma
+
+
+def test_deeper_attributes():
+    collection = af.Collection(
+        model=af.Model(af.Gaussian, centre=0.0, normalization=1.0, sigma=-1.0,)
+    )
+
+    instance_1 = af.Collection(
+        t=1.0, collection=collection,
+    ).instance_from_prior_medians()
+    instance_2 = af.Collection(
+        t=2.0, collection=collection,
+    ).instance_from_prior_medians()
+
+    time_series = af.LinearInterpolator([instance_1, instance_2])
+
+    result = time_series[time_series.t == 1.5]
+
+    assert result.collection.model.centre == 0.0
+    assert result.collection.model.normalization == 1.0
+    assert result.collection.model.sigma == -1.0