/// <summary>
/// calculate center list in detail for the given user
/// </summary>
/// <param name="uid"></param>
/// <returns>returns list(center),包括center的id，空间范围，poi列表</returns>
public List <Center> Center_list2(string uid, double d = 0.1, double theta = 0.05)
{
//check whether datasets have been loaded
if (!ds.isInitialized())
{
Initial();
}
//sort user's check-in POI by check-in frequency
var temp = from item in usercheckins[uid] orderby item.Value descending select item;
var poi_list = new List <string>();
foreach (var item in temp)
{
poi_list.Add(item.Key);
}
//store POIs which have already been clustered
Dictionary <string, string> POI_Center = new Dictionary <string, string>();
//retult list store all <centers,check-in probability> for the given uid
var center_list = new List <Center>();
//temp center list for a center
var curr_center = new List <string>();
int center_no = 0; //当前 center 的index
int total_freq = 0; //指定 user 在该 center 的签到数目
for (int i = 0; i < poi_list.Count; i++)
{
if (!POI_Center.ContainsKey(poi_list[i]))
{
//reset regional variables
center_no++;
curr_center.Clear();
total_freq = 0;
curr_center.Add(poi_list[i]);
total_freq += usercheckins[uid][poi_list[i]];
//设定当前center的spatial range
rectangle rec = new rectangle(POIcategory[poi_list[i]].Item1,
POIcategory[poi_list[i]].Item2, POIcategory[poi_list[i]].Item1,
POIcategory[poi_list[i]].Item2);
for (int j = i + 1; j < poi_list.Count; j++)
{
if ((!POI_Center.ContainsKey(poi_list[j])) & (
DistanceOfTwoPoints(POIcategory[poi_list[i]].Item1, POIcategory[poi_list[i]].Item2,
POIcategory[poi_list[j]].Item1, POIcategory[poi_list[j]].Item2, GaussSphere.WGS84) < d))
{
curr_center.Add(poi_list[j]);
total_freq += usercheckins[uid][poi_list[j]];
//更新rec范围
rec.update(POIcategory[poi_list[j]].Item1, POIcategory[poi_list[j]].Item2);
}
}
if (total_freq >= (usercheckins[uid].Values.Sum() * theta))//满足center条件
{
//center_list.Add(poi_list[i], (total_freq / (usercheckins[uid].Values.Sum() + 0.0)));
var cent = new Center(poi_list[i], rec, curr_center);
center_list.Add(cent);
foreach (var item in curr_center)
{
POI_Center.Add(item, poi_list[i]);
}
}
}
}
return(center_list);
}
public List <string> poi_list; //中心选择时属于该center的POI
//public Dictionary<string, List<string>> cate_poi;//用户在该中心访问过的 类型，POI集合
public Center(string id, rectangle sp, List <string> poi_list)
{
this.c_id = id;
this.sp = sp;
this.poi_list = poi_list;
}
