Localization　is　a　fundamental　and　vital　problem　in　wireless　sensor　networks.　This　paper　presents　an　optimizing　framework　for　localization　based　on　barycentric　coordinates.　The　framework　consists　of　two　components.　The　first　component　retains　the　structure　revealed　by　the　distances　between　pairs　of　nodes;　the　second　component　constrains　the　boundary　nodes　to　maintain　the　distance　with　their　neighbor　nodes.　A　hybrid　localization　algorithm　is　derived　on　top　of　the　optimizing　framework.　A　part　of　the　computation　is　performed　collaboratively　by　nodes,　whereas　the　rest　is　executed　on　the　sink　node.　Experimental　results　show　that　the　proposed　localization　algorithm　obtains　lower　location　errors　without　higher　communication　costs.　(C)　2013　Elsevier　B.V.　All　rights　reserved.