dev (#275)

closes issues #267 #274, #255, #256

Co-authored-by: Dominik Demuth <dominik.demuth@physik.tu-darmstadt.de>
Reviewed-on: #275

src/gui_qt/data/valueeditwidget.py

@@ -385,6 +385,6 @@ class ValueModel(QtCore.QAbstractTableModel):
     @staticmethod
     def as_string(value) -> str:
         if isinstance(value, complex):
-            return f'{value.real:.8g}{value.imag:+.8g}j'
+            return f'{value.real:.13g}{value.imag:+.13g}j'
         else:
-            return f'{value:.8g}'
+            return f'{value:.13g}'