/// <summary>
/// Returns percent overlap.
/// Gets lists of question or requirement IDs, then uses LINQ to do the intersection.
/// </summary>
/// <param name="mode"></param>
/// <returns></returns>
private float CalcCompatibility(string mode, List <int> assessmentIds)
{
var l = new List <List <int> >();
// master hash set of all questions
var m = new HashSet <int>();
using (var db = new CSET_Context())
{
foreach (int id in assessmentIds)
{
if (mode == "Q")
{
var listQuestionID = (List <int>)db.InScopeQuestions(id);
l.Add(listQuestionID);
m.UnionWith(listQuestionID);
}
if (mode == "R")
{
var listRequirementID = (List <int>)db.InScopeRequirements(id);
l.Add(listRequirementID);
m.UnionWith(listRequirementID);
}
}
}
if (l.Count == 0)
{
return(0f);
}
var intersection = l
.Skip(1)
.Aggregate(
new HashSet <int>(l.First()),
(h, e) => { h.IntersectWith(e); return(h); }
);
if (m.Count == 0)
{
return(0f);
}
return((float)intersection.Count / (float)m.Count);
}
