minor bug fix.
minor bug fix.


nathania/pysal,darribas/pysal,sjsrey/pysal_core,badjr/pysal,jlaura/pysal,spreg-git/pysal,badjr/pysal,sjsrey/pysal_core,ljwolf/pysal_core,pysal/pysal,lanselin/pysal,hasecbinusr/pysal,pastephens/pysal,nathania/pysal,schmidtc/pysal,dfolch/pysal,jlaura/pysal,ljwolf/pysal,ljwolf/pysal_core,ljwolf/pysal_core,TaylorOshan/pysal,ljwolf/pysal,TaylorOshan/pysal,lixun910/pysal,schmidtc/pysal,sjsrey/pysal_core,pastephens/pysal,pedrovma/pysal,hasecbinusr/pysal,lixun910/pysal,chhao91/pysal,hasecbinusr/pysal,chhao91/pysal,dfolch/pysal,TaylorOshan/pysal,jlaura/pysal,darribas/pysal,spreg-git/pysal,pastephens/pysal,lixun910/pysal,sjsrey/pysal,ljwolf/pysal,weikang9009/pysal