bug fix

README.md

@@ -76,8 +76,14 @@ class TransformersUD(object):
     for i in range(n):
       for j in range(n):
         m[i+1,0 if i==j else j+1]=s[i][b[i][j]]+e[i][b[i][j+1]-1]
-    m[:,0]=numpy.where(m[:,0]==numpy.nanmax(m[:,0]),0,numpy.nan)
     h=ufal.chu_liu_edmonds.chu_liu_edmonds(m)[0]
+    if [0 for i in h if i==0]!=[0]:
+      try:
+        i=[p for s,e,p in w].index("root")+1
+      except:
+        i=numpy.nanargmax(m[:,0])
+      m[0:i,0]=m[i+1:,0]=numpy.nan
+      h=ufal.chu_liu_edmonds.chu_liu_edmonds(m)[0]
     u="# text = "+text.replace("\n"," ")+"\n"
     for i,(s,e,p) in enumerate(w,1):
       p="root" if h[i]==0 else "dep" if p=="root" else p