diff --git a/src/dynamic_graph/signal_base.py b/src/dynamic_graph/signal_base.py
index aa3367ccf18ccfea6c9b25f8324bbc301182e1f3..71e69bee0ab1167bd7fc46167a9f02e8877e3415 100644
--- a/src/dynamic_graph/signal_base.py
+++ b/src/dynamic_graph/signal_base.py
@@ -6,14 +6,13 @@
 import wrap
 import re
 
-def stringToTuple(vector):
+def stringToTuple (vector) :
     """
-    Transform a string of format '[n](x_1, x_2, ..., x_{n-1}) into a list of
-    numbers
+    Transform a string of format '[n](x_1,x_2,...,x_n)' into a tuple of numbers.
     """
     # Find vector length
-    a = re.search('[\d]', vector)
-    size = int(a.group(0))
+    a = re.match('\[(\d+)\]',vector)
+    size = int(a.group(1))
     format = '\('
     for i in range(size):
         format += '(.*)'
@@ -22,17 +21,125 @@ def stringToTuple(vector):
     format += '\)'
     a = re.search(format, vector)
     res = []
-    for i in range(1, size+1):
-        res.append(float(a.group(i)))
-    return tuple(res)
+    for i in range (1, size+1):
+        res.append (float(a.group(i)))
+    return tuple (res)
 
-def tupleToString(vector):
-    string = '[%d]('%len(vector)
+def tupleToString (vector) :
+    """
+    Transform a tuple of numbers into a string of format
+    '[n](x_1, x_2, ..., x_n)'
+    """
+    string = '[%d]('%len (vector)
     for x in vector[:-1]:
         string += '%f,'%x
     string += '%f)'%vector[-1]
     return string
 
+def stringToMatrix (string) :
+    """
+    Transform a string of format
+    '[n,m]((x_11,x_12,...,x_1m),...,(x_n1,x_n2,...,x_nm))' into a tuple
+    of tuple of numbers.
+    """
+    # Find matrix size
+    a = re.search ('\[(\d+),(\d+)]', string)
+    nRows = int (a.group(1))
+    nCols = int (a.group(2))
+    format = '\('
+    for row in range (nRows) :
+        format += '\('
+        for col in range (nCols) :
+            format += '(.*)'
+            if col != nCols-1 :
+                format += ','
+        format += '\)'
+        if row != nRows-1 :
+            format += ','
+    format += '\)'
+    a = re.search (format, string)
+    m = []
+    index = 1
+    for r in range (nRows) :
+        row = []
+        for c in range (nCols) :
+            row.append (float (a.group (index)))
+            index += 1
+        m.append (tuple (row))
+    return tuple (m)
+
+def matrixToString(matrix) :
+    """
+    Transform a tuple of tuple of numbers into a string of format
+    '[n,m]((x_11,x_12,...,x_1m),...,(x_n1,x_n2,...,x_nm))'.
+    """
+    nRows = len(matrix)
+    if nRows is 0 :
+        return '[0,0](())'
+    nCols = len(matrix[0])
+    string = '[%d,%d](' % (nRows, nCols)
+    for r in range (nRows) :
+        string += '('
+        for c in range (nCols) :
+            string += str (float (matrix [r][c]))
+            if c != nCols-1 :
+                string += ','
+        string += ')'
+        if r != nRows -1 :
+            string += ','
+    string += ')'
+    return string
+
+def objectToString(obj) :
+    """
+    Transform an object to a string. Object is either
+      - a floating point number,
+      - an integer,
+      - a boolean,
+      - a vector or
+      - a matrix
+    """
+    if (isinstance(obj, tuple)) :
+        # matrix or vector
+        if len(obj) is 0 :
+            return ""
+        else :
+            if (isinstance(obj[0], tuple)) :
+                #matrix
+                return matrixToString(obj)
+            else :
+                #vector
+                return tupleToString(obj)
+    else :
+        return str(obj)
+
+def stringToObject(string) :
+    """
+    Convert a string into one of the following types
+      - a matrix (tuple of tuple),
+      - a vector,
+      - an integer,
+      - a floating point number.
+    Successively attempts conversion in the above order and return
+    on success. If no conversion fits, the string is returned.
+    """
+    try :
+        return stringToMatrix(string)
+    except :
+        pass
+    try :
+        return stringToTuple(string)
+    except :
+        pass
+    try :
+        return int(string)
+    except :
+        pass
+    try :
+        return float(string)
+    except :
+        return string
+
 class SignalBase (object) :
     """
     This class binds dynamicgraph::SignalBase<int> C++ class
@@ -62,7 +169,8 @@ class SignalBase (object) :
         """
         Read the value of a signal
         """
-        return wrap.signal_base_get_value(self.object)
+        string = wrap.signal_base_get_value(self.object)
+        return stringToObject(string)
 
     @value.setter
     def value(self, val) :
@@ -70,4 +178,5 @@ class SignalBase (object) :
         Set the signal as a constant signal with given value.
         If the signal is plugged, it will be unplugged
         """
-        return wrap.signal_base_set_value(self.object, val)
+        string = objectToString(val)
+        return wrap.signal_base_set_value(self.object, string)