openlayers3 实现地图归心功能

function centerFunc() {
    var pan = ol.animation.pan({
        duration: 1000,     //动画持续时间,默认是1000
        source: map.getView().getCenter(),
        easing: ol.easing.easeOut,   // 要使用的动画功能,能够是ol.easing自定义函数
    });
    map.beforeRender(pan);
    map.getView().setZoom(8);
    map.getView().setCenter([12335101.876548603, 2129841.356138151]);
}