public static double MEI_Calc(CATItems itemBank, int item, int[] x, double theta, CATItems it_given, string model = null, string method = "BM", double D = 1, double[] priorPar = null, string priorDist = "norm", double[] range = null, int[] parInt = null, int infoType = 2 /* Observed */)
{
double res = 0;
if (priorPar == null || priorPar.Length < 2)
{
priorPar = new double[2];
priorPar[0] = 0;
priorPar[1] = 1;
}
if (parInt == null || parInt.Length < 3)
{
parInt = new int[3];
parInt[0] = -4;
parInt[1] = 4;
parInt[2] = 33;
}
if (range == null || range.Length < 2)
{
range = new double[2];
range[0] = -4;
range[1] = 4;
}
if ((infoType == (int)ModelNames.InfoType.Observed) || (infoType == (int)ModelNames.InfoType.Fisher)) // type is either "Observed" or "Fisher"
{
double th = theta;
// Finding desired "item" from itembank & Added to given items "it_given".
// Instead of "itj", "it_given" will be used.
itemBank.AddItem(it_given, item);
if (String.IsNullOrEmpty(model)) // Dichotomous Items
{
List <int> temp_x = x.ToList();
temp_x.Add(0);
double th0 = CatRcs.ThetaEST.ThetaEst_Calc(it_given, temp_x.ToArray(), D: D, model: model, method: method, priorPar: priorPar, priorDist: priorDist, parInt: parInt, range: range);
temp_x = x.ToList();
temp_x.Add(1);
double th1 = CatRcs.ThetaEST.ThetaEst_Calc(it_given, temp_x.ToArray(), D: D, model: model, method: method, priorPar: priorPar, priorDist: priorDist, parInt: parInt, range: range);
double p1 = CatRcs.Pi.Pi_Calc(th, itemBank.FindItem(item), model, D).Pi.First();
double p0 = 1 - p1;
double Ij0 = 0, Ij1 = 0;
if ((infoType == (int)ModelNames.InfoType.Fisher))
{
Ij0 = CatRcs.Ii.Ii_Calc(th0, itemBank.FindItem(item), model, D).Ii.First();
Ij1 = CatRcs.Ii.Ii_Calc(th1, itemBank.FindItem(item), model, D).Ii.First();
}
else
{
Ij0 = CatRcs.OIi.OIi_Calc(th0, itemBank.FindItem(item), new int[] { 0 }, model, D).OIi.First();
Ij1 = CatRcs.OIi.OIi_Calc(th1, itemBank.FindItem(item), new int[] { 1 }, model, D).OIi.First();
}
res = (p0 * Ij0) + (p1 * Ij1);
}
else // Polytomous Items
{
double[,] probs = Pi.Pi_Poly_Calc(theta, itemBank.FindItem(item), model, D).Pi;
double[] Ii_new = new double[probs.GetLength(1)];
for (int j = 0; j < probs.GetLength(1); j++) // column iteration
{
List <int> temp_x = x.ToList();
temp_x.Add(j);
double th_new = CatRcs.ThetaEST.ThetaEst_Calc(it_given, temp_x.ToArray(), D: D, model: model, method: method, priorPar: priorPar, priorDist: priorDist, parInt: parInt, range: range);
if ((infoType == (int)ModelNames.InfoType.Fisher))
{
Ii_new[j] = CatRcs.Ii.Ii_Calc(th_new, itemBank.FindItem(item), model, D).Ii.First();
}
else
{
Ii_new[j] = CatRcs.OIi.OIi_Calc(th_new, itemBank.FindItem(item), new int[] { j }, model, D).OIi.First();
}
}
res = CatRcs.Utils.RowColumn.Sum(Ii_new.ToList().Select((p, i) => p * probs[0, i]).ToArray());
}
}
else
{
return(res);
}
return(res);
}
