[Avida-SVN] r3319 - development/source/actions

[beckma24 at myxo.css.msu.edu]

Author: beckma24
Date: 2009-06-15 15:30:39 -0400 (Mon, 15 Jun 2009)
New Revision: 3319

Modified:
   development/source/actions/PopulationActions.cc
Log:
Minor enhancement it nand anti-avidian treatment

Modified: development/source/actions/PopulationActions.cc
===================================================================
--- development/source/actions/PopulationActions.cc	2009-06-12 19:37:02 UTC (rev 3318)
+++ development/source/actions/PopulationActions.cc	2009-06-15 19:30:39 UTC (rev 3319)
@@ -955,7 +955,13 @@
 				// count the number of target instructions in the genome
 				int count = cGenomeUtil::CountInst(cell.GetOrganism()->GetGenome(), m_world->GetHardwareManager().GetInstSet().GetInst(m_inst));
 
-				double killprob = min(pow(m_exprWeight*count,m_exponent), 100.0)/100.0;
+				double killprob;
+				
+				if(m_exponent == -1.0)
+					killprob = min(1.0/(m_exprWeight+ pow(M_E, -count)), 100.0)/100.0;  //sigmoid
+				else
+					killprob = min(pow(m_exprWeight*count,m_exponent), 100.0)/100.0;  // linear and exponential
+				
 				// cout << count << " " << killprob << endl;
 				currentKillProb.Add(killprob);
 				// decide if it should be killed or not, based on the kill probability