fixed bug in topk
fixed bug in topk

git-svn-id: 16fdb7d2a4f608102f2cc0f4db15fb5e8b3d4ed7@24096 c9c46bb1-2420-0410-b6d5-8c78f6715463

mredaelli/breeze,claydonkey/breeze,ktakagaki/breeze,ktakagaki/breeze,cilier/breeze,scalanlp/breeze,tjhunter/scalanlp-core,nikdon/breeze,wstcpyt/breeze,sheide/breeze,ContentSquare/breeze,tjhunter/scalanlp-core,calippo/breeze,crealytics/breeze,chen0031/breeze,eponvert/breeze