trac #16361: Merged with #16388

src/sage/combinat/designs/bibd.py

@@ -118,7 +118,7 @@ def BalancedIncompleteBlockDesign(v,k,existence=False,use_LJCR=False):
         sage: designs.BalancedIncompleteBlockDesign(16,6)
         Traceback (most recent call last):
         ...
-        NotImplementedError: I don't know how to build this design.
+        NotImplementedError: I don't know how to build a (16,6,1)-BIBD!
 
     TESTS::
 
@@ -222,7 +222,7 @@ def BalancedIncompleteBlockDesign(v,k,existence=False,use_LJCR=False):
     if existence:
         return Unknown
     else:
-        raise NotImplementedError("I don't know how to build this design.")
+        raise NotImplementedError("I don't know how to build a ({},{},1)-BIBD!".format(v,k))
 
 def steiner_triple_system(n):
     r"""
@@ -383,7 +383,7 @@ def BIBD_from_TD(v,k,existence=False):
         sage: BIBD_from_TD(20,5)
         Traceback (most recent call last):
         ...
-        NotImplementedError: I do not know how to build this BIBD!
+        NotImplementedError: I do not know how to build a (20,5,1)-BIBD!
     """
     from orthogonal_arrays import transversal_design
 
@@ -446,10 +446,9 @@ def BIBD_from_TD(v,k,existence=False):
     # No idea ...
     else:
         if existence:
-            from sage.misc.unknown import Unknown
             return Unknown
         else:
-            raise NotImplementedError("I do not know how to build this BIBD!")
+            raise NotImplementedError("I do not know how to build a ({},{},1)-BIBD!".format(v,k))
 
     return BIBD
 

src/sage/combinat/designs/latin_squares.py

@@ -265,7 +265,7 @@ def mutually_orthogonal_latin_squares(n,k, partitions = False, check = True, exi
         sage: designs.mutually_orthogonal_latin_squares(6, 4)
         Traceback (most recent call last):
         ...
-        NotImplementedError: I don't know how to build these MOLS!
+        NotImplementedError: I don't know how to build 4 MOLS of order 6
 
     TESTS:
 
@@ -339,7 +339,7 @@ def mutually_orthogonal_latin_squares(n,k, partitions = False, check = True, exi
         else:
             if existence:
                 return False
-            raise EmptySetError("These MOLS do not exist!")
+            raise EmptySetError("There does not exist {} MOLS of order {}!".format(k,n))
 
         OA = orthogonal_array(k+2,n,check=False, who_asked = who_asked+(mutually_orthogonal_latin_squares,))
         OA.sort() # make sure that the first two columns are "11, 12, ..., 1n, 21, 22, ..."
@@ -357,7 +357,7 @@ def mutually_orthogonal_latin_squares(n,k, partitions = False, check = True, exi
     else:
         if existence:
             return Unknown
-        raise NotImplementedError("I don't know how to build these MOLS!")
+        raise NotImplementedError("I don't know how to build {} MOLS of order {}".format(k,n))
 
     if check:
         assert are_mutually_orthogonal_latin_squares(matrices)

src/sage/combinat/designs/orthogonal_arrays.py

@@ -161,11 +161,11 @@ def transversal_design(k,n,check=True,existence=False, who_asked=tuple()):
         sage: designs.transversal_design(47, 100)
         Traceback (most recent call last):
         ...
-        NotImplementedError: I don't know how to build this Transversal Design!
+        NotImplementedError: I don't know how to build a TD(47,100)!
         sage: designs.transversal_design(55, 54)
         Traceback (most recent call last):
         ...
-        EmptySetError: There exists no TD(55, 54)!
+        EmptySetError: There exists no TD(55,54)!
 
     Those two errors correspond respectively to the cases where Sage answer
     ``Unknown`` or ``False`` when the parameter ``existence`` is set to
@@ -319,15 +319,15 @@ def transversal_design(k,n,check=True,existence=False, who_asked=tuple()):
         else:
             if existence:
                 return False
-            raise EmptySetError("There exists no TD"+str((k,n))+"!")
+            raise EmptySetError("There exists no TD({},{})!".format(k,n))
 
         OA = orthogonal_array(k,n, check = False, who_asked = who_asked + (transversal_design,))
         TD = [[i*n+c for i,c in enumerate(l)] for l in OA]
 
     else:
         if existence:
             return Unknown
-        raise NotImplementedError("I don't know how to build this Transversal Design!")
+        raise NotImplementedError("I don't know how to build a TD({},{})!".format(k,n))
 
     if check:
         assert is_transversal_design(TD,k,n)
@@ -789,7 +789,7 @@ def orthogonal_array(k,n,t=2,check=True,existence=False,who_asked=tuple()):
         sage: designs.orthogonal_array(12,20)
         Traceback (most recent call last):
         ...
-        NotImplementedError: I don't know how to build this orthogonal array!
+        NotImplementedError: I don't know how to build an OA(12,20)!
 
     Note that these errors correspond respectively to the answers ``False`` and
     ``Unknown`` when the parameter ``existence`` is set to ``True``::
@@ -902,7 +902,7 @@ def orthogonal_array(k,n,t=2,check=True,existence=False,who_asked=tuple()):
         else:
             if existence:
                 return False
-            raise EmptySetError("There exists no OA"+str((k,n))+"!")
+            raise EmptySetError("There exists no OA({},{})!".format(k,n))
 
     # Section 6.5.1 from [Stinson2004]
     elif (t == 2 and mutually_orthogonal_latin_squares not in who_asked and
@@ -920,12 +920,12 @@ def orthogonal_array(k,n,t=2,check=True,existence=False,who_asked=tuple()):
         else:
             if existence:
                 return False
-            raise EmptySetError("There exists no OA"+str((k,n))+"!")
+            raise EmptySetError("There exists no OA({},{})!".format(k,n))
 
     else:
         if existence:
             return Unknown
-        raise NotImplementedError("I don't know how to build this orthogonal array!")
+        raise NotImplementedError("I don't know how to build an OA({},{})!".format(k,n))
 
     if check:
         assert is_orthogonal_array(OA,k,n,t)