/// <summary>
/// GetMaxGainRatio
/// </summary>
/// <param name="value_decision_list"></param>
/// <returns></returns>
static IntDouble GetMaxGainRatioInContinuous(string[] S, int index_collumn, double entropy_main)
{
List <int> values = new List <int>();
List <IntString> new_data = new List <IntString>();
for (int i = 0; i <= S.Length - 1; i++)
{
string[] words = S[i].Split(',');
values.Add(int.Parse(words[index_collumn]));
new_data.Add(new IntString(int.Parse(words[index_collumn]), words.Last()));
}
values = values.Distinct().OrderBy(x => x).ToList();
List <IntDouble> gain_ratio_each_value = new List <IntDouble>();
foreach (int value in values.Distinct().ToList())
{
double gain_ratio = GetGainRatio(entropy_main, new_data, value);
gain_ratio_each_value.Add(new IntDouble(value, gain_ratio));
}
double value_max = gain_ratio_each_value.Max(x => x.Value);
IntDouble rs = gain_ratio_each_value.Where(x => x.Value == value_max).FirstOrDefault();
return(rs);
}
static string[] ConvertContinuous(string[] S, List <int> index_collumns, double entropy_main)
{
List <string> S_new = new List <string>();
foreach (int index in index_collumns)
{
IntDouble final = GetMaxGainRatioInContinuous(S, index, entropy_main);
List <int> values = new List <int>();
List <IntString> new_data = new List <IntString>();
S_new = new List <string>();
for (int i = 0; i <= S.Length - 1; i++)
{
string[] words = S[i].Split(',');
if (int.Parse(words[index]) <= final.Key)
{
words[index] = "<=" + final.Key.ToString();
}
else
{
words[index] = ">" + final.Key.ToString();
}
S_new.Add(String.Join(",", words));
}
S = S_new.ToArray();
}
return(S_new.ToArray());
}
private static IntDouble MakeDecision(string[] S, double entropy_main)
{
List <IntDouble> listGainRatio = new List <IntDouble>();
for (int i = 0; i <= S[0].Split(',').Length - 2; i++)
{
List <StringString> dataset = new List <StringString>();
for (int j = 0; j <= S.Length - 1; j++)
{
string[] words = S[j].Split(',');
StringString obj = new StringString(words[i], S[j].Split(',')[words.Length - 1]);
dataset.Add(obj);
}
IntDouble gain_ratio = new IntDouble(i, GetGainRatioMain(entropy_main, dataset));
listGainRatio.Add(gain_ratio);
}
double max_gain_ratio = listGainRatio.Max((x => x.Value));
return(listGainRatio.Where(x => x.Value == max_gain_ratio).FirstOrDefault());
}