diff --git a/src/wela/dataloader.py b/src/wela/dataloader.py
index f19a8e0c1ef9a7a74bd7fb3ff66d82fb25916cb5..44570b4414f0452df94a5f25eee547e86ca681e2 100644
--- a/src/wela/dataloader.py
+++ b/src/wela/dataloader.py
@@ -76,40 +76,49 @@ class dataloader:
 
     def __init__(self, h5dir=None, wdir=".", ls=True):
         # from grouper.signals to abbreviations
-        self.g2a_dict = {
+        self.g2a_dict = self.define_g2a_dict()
+        # from abbreviations to grouper.siglist
+        self.a2g_dict = {v: k for (k, v) in self.g2a_dict.items()}
+        # establish paths
+        self.wdirpath = Path(wdir)
+        if h5dir is None:
+            self.h5dirpath = None
+        else:
+            self.h5dirpath = Path(h5dir)
+        if ls:
+            self.ls
+
+    def define_g2a_dict(self):
+        """Dict to convert names of grouper.signals to short forms."""
+        g2a_dict = {
             "extraction/cy5/max/median": "cy5",
             "extraction/general/None/area": "area",
             "extraction/general/None/volume": "volume",
+            "extraction/general/None/image_x": "image_x",
+            "extraction/general/None/image_y": "image_y",
+            "extraction/general/None/absolute_x": "absolute_x",
+            "extraction/general/None/absolute_y": "absolute_y",
             "extraction/Flavin_bgsub/max/mean": "flavin",
             "postprocessing/buddings/extraction_general_None_volume": "buddings",
             "postprocessing/bud_metric/extraction_general_None_volume": "bud_volume",
         }
         for fl in ["GFP", "mCherry"]:
-            self.g2a_dict[f"extraction/{fl}/max/median"] = f"median_{fl}"
-            self.g2a_dict[f"extraction/{fl}/max/mean"] = f"mean_{fl}"
-            self.g2a_dict[f"extraction/{fl}/max/std"] = f"std_{fl}"
-            self.g2a_dict[f"extraction/{fl}/max/max5px_median"] = (
+            g2a_dict[f"extraction/{fl}/max/median"] = f"median_{fl}"
+            g2a_dict[f"extraction/{fl}/max/mean"] = f"mean_{fl}"
+            g2a_dict[f"extraction/{fl}/max/std"] = f"std_{fl}"
+            g2a_dict[f"extraction/{fl}/max/max5px_median"] = (
                 f"max5px_median_{fl}"
             )
-            self.g2a_dict[
+            g2a_dict[
                 f"postprocessing/bud_metric/extraction_{fl}_max_median"
             ] = f"bud_median_{fl}"
-            self.g2a_dict[
-                f"postprocessing/bud_metric/extraction_{fl}_max_mean"
-            ] = f"bud_mean_{fl}"
-            self.g2a_dict[
-                f"postprocessing/bud_metric/extraction_{fl}_max_std"
-            ] = f"bud_std_{fl}"
-        # from abbreviations to grouper.siglist
-        self.a2g_dict = {v: k for (k, v) in self.g2a_dict.items()}
-        # establish paths
-        self.wdirpath = Path(wdir)
-        if h5dir is None:
-            self.h5dirpath = None
-        else:
-            self.h5dirpath = Path(h5dir)
-        if ls:
-            self.ls
+            g2a_dict[f"postprocessing/bud_metric/extraction_{fl}_max_mean"] = (
+                f"bud_mean_{fl}"
+            )
+            g2a_dict[f"postprocessing/bud_metric/extraction_{fl}_max_std"] = (
+                f"bud_std_{fl}"
+            )
+        return g2a_dict
 
     @property
     def ls(self):
@@ -283,7 +292,7 @@ class dataloader:
                 print(" ", signal)
             print()
             if self.a2g_dict[key_index] not in grouper.available:
-                raise Exception(f"the key index {key_index} is unavailable.")
+                raise Exception(f"The key index {key_index} is unavailable.")
             # get indices for all buds
             bud_indices = self.get_bud_indices(grouper, key_index)
             # get key_index data