diff --git a/src/dynamic_graph/signal_base.py b/src/dynamic_graph/signal_base.py
index dc3e144ded6ce70b8355cf112847ec587b77d40c..109cf20360ce61775f96debb658e27eff36c5191 100644
--- a/src/dynamic_graph/signal_base.py
+++ b/src/dynamic_graph/signal_base.py
@@ -126,6 +126,9 @@ def stringToObject(string) :
     Successively attempts conversion in the above order and return
     on success. If no conversion fits, the string is returned.
     """
+    if isinstance(string,float): return string
+    if isinstance(string,int): return string
+    if isinstance(string,tuple): return string
     try :
         return stringToMatrix(string)
     except :