Changeset 6218:13d465b1abc8

Timestamp:

09/06/07 13:10:45 (6 years ago)

Author:

Robert Bradshaw <robertwb@…>

Branch:

default

Message:

fix permgroup_element.word_problem() to coerce self into group generated by words

Location:

sage/groups/perm_gps

Files:

• cubegroup.py (modified) (2 diffs)
• permgroup_element.py (modified) (2 diffs)

sage/groups/perm_gps/cubegroup.py

@@ -11 +11 @@
           Products of moves are read {\it right to left}, so for example,
           R*U means move U first and then R.
+          
+See \code{CubeGroup.parse()} for all possible input notations. 
           
 The "Singmaster notation": 
@@ -1065 +1067 @@
         soln = hom.PreImagesRepresentative(gap(str(g)))
         # print soln
-        sol1 = str(soln).replace("x1","B")
-        sol2 = sol1.replace("x2","D")
-        sol3 = sol2.replace("x3","F")
-        sol4 = sol3.replace("x4","L")
-        sol5 = sol4.replace("x5","R")
-        sol6 = sol5.replace("x6","U")
-        return sol6
-
+        sol = str(soln)
+        names = self.gen_names()
+        for i in range(6):
+            sol = sol.replace("x%s" % (i+1), names[i])
+        return sol
 
 

sage/groups/perm_gps/permgroup_element.py

@@ -535 +535 @@
         from sage.groups.perm_gps.permgroup import PermutationGroup
         from sage.interfaces.all import gap
-        G = g.parent()
-        #print G
-        gap.eval("l:=One(Rationals)")
-        s1 = "gens := GeneratorsOfGroup(%s)"%G._gap_init_()
-        #print s1
-        gap.eval(s1)
-        s2 = "g0:=%s; gensH:=%s"%(gap(g),words)
-        gap.eval(s2)
-        s3 = 'G:=Group(gens); H:=Group(gensH)'
-        #print s3
-        gap.eval(s3)
-        phi = gap.eval("hom:=EpimorphismFromFreeGroup(G)")
-        #print phi
-        l1 = gap.eval("ans:=PreImagesRepresentative(hom,g0)")
+        
+        G = gap(words[0].parent())
+        g = words[0].parent()(g)
+        gensH = gap(words)
+        H = gensH.Group()
+        hom = G.EpimorphismFromFreeGroup()
+        ans = hom.PreImagesRepresentative(gap(g))
+        
+        l1 = str(ans)
         l2 = copy.copy(l1)
         l4 = []
@@ -554 +549 @@
         for i in range(1,len(words)+1):
             l2 = l2.replace("x"+str(i),str(words[i-1]))
+
         if display:
             for i in range(len(l3)):    ## parsing the word for display