Added experimental dixon Q test rejection strategy

shogun-toolbox · Apr 28, 2012 · 667fcd5 · 667fcd5
1 parent 00f3b79
commit 667fcd5
Showing 1 changed file with 102 additions and 5 deletions.
diff --git a/src/shogun/features/RejectionStrategy.h b/src/shogun/features/RejectionStrategy.h
@@ -36,24 +36,24 @@ class CRejectionStrategy : public CSGObject
 };
 
 /** @brief threshold based rejection strategy */
-class CThresholdReject : public CRejectionStrategy
+class CThresholdRejectionStrategy : public CRejectionStrategy
 {
 	public:
 
 		/** constructor */
-		CThresholdReject() :
+		CThresholdRejectionStrategy() :
 			CRejectionStrategy(), m_threshold(0.0) { };
 
 		/** constructor */
-		CThresholdReject(float64_t threshold) :
+		CThresholdRejectionStrategy(float64_t threshold) :
 			CRejectionStrategy(), m_threshold(threshold) { };
 
-		virtual ~CThresholdReject() {};
+		virtual ~CThresholdRejectionStrategy() {};
 
 		/** get name */
 		virtual const char* get_name() const
 		{
-				return "ThresholdReject";
+			return "ThresholdRejectionStrategy";
 		}
 
 		/** returns true if given output set leads to rejection */
@@ -74,5 +74,102 @@ class CThresholdReject : public CRejectionStrategy
 
 
 };
+
+static const float64_t Q_test_statistic_values[10][8] = 
+{
+	/* 10,20,30,40,50,60,70,80,90,100 */
+	{0.713,0.683,0.637,0.597,0.551,0.477,0.409,0.325},
+	{0.627,0.604,0.568,0.538,0.503,0.450,0.401,0.339},
+	{0.539,0.517,0.484,0.456,0.425,0.376,0.332,0.278},
+	{0.490,0.469,0.438,0.412,0.382,0.337,0.295,0.246},
+	{0.460,0.439,0.410,0.384,0.355,0.312,0.272,0.226},
+	{0.437,0.417,0.388,0.363,0.336,0.294,0.256,0.211},
+	{0.422,0.403,0.374,0.349,0.321,0.280,0.244,0.201},
+	{0.408,0.389,0.360,0.337,0.310,0.270,0.234,0.192},
+	{0.397,0.377,0.350,0.326,0.300,0.261,0.226,0.185},
+	{0.387,0.368,0.341,0.317,0.292,0.253,0.219,0.179}
+};
+
+/** @brief simplified version of Dixon's Q test outlier based
+ * rejection strategy. Statistic values are taken from
+ * http://www.vias.org/tmdatanaleng/cc_outlier_tests_dixon.html
+ * */
+class CDixonQRejectionStrategy : public CRejectionStrategy
+{
+	public:
+
+		/** constructor */
+		CDixonQRejectionStrategy() :
+			CRejectionStrategy()
+		{
+			s_index = 3;
+		}
+
+		/** constructor 
+		 * @param significance_level either 0.001,0.002,0.005,
+		 * 0.01,0.02,0.05,0.1 or 0.2 
+		 */
+		CDixonQRejectionStrategy(float64_t significance_level) :
+			CRejectionStrategy()
+		{	
+			if (significance_level==0.001)
+				s_index = 0;
+			else if (significance_level==0.002)
+				s_index = 1;
+			else if (significance_level==0.005)
+				s_index = 2;
+			else if (significance_level==0.01)
+				s_index = 3;
+			else if (significance_level==0.02)
+				s_index = 4;
+			else if (significance_level==0.05)
+				s_index = 5;
+			else if (significance_level==0.1)
+				s_index = 6;
+			else if (significance_level==0.2)
+				s_index = 7;
+			else SG_ERROR("Given significance level is not supported");
+		}
+
+		virtual ~CDixonQRejectionStrategy() 
+		{
+		}
+
+		/** get name */
+		virtual const char* get_name() const
+		{
+			return "DixonQTestRejectionStrategy";
+		}
+
+		/** returns true if given output set leads to rejection */
+		virtual bool reject(const SGVector<float64_t>& outputs) const
+		{
+			int32_t N = outputs.vlen;
+			if (N<10 || N>100) 
+				SG_ERROR("Given number of classes is not supported.");
+
+			int32_t Ni = N/10 - 1;
+
+			CMath::qsort(outputs.vector,N);
+
+			float64_t Q = 0.0;
+			if (N==10)
+				Q = (outputs[N-1]-outputs[N-2])/(outputs[N-1]-outputs[0]);
+
+			if (N>=20)
+				Q = (outputs[N-1]-outputs[N-4])/(outputs[N-1]-outputs[2]);
+
+			if (Q>Q_test_statistic_values[Ni][s_index])
+				return false;
+
+			return true;
+		}
+
+private:
+
+		int32_t s_index;
+
+};
+
 }
 #endif