Index: /issm/trunk/src/m/classes/public/graddetection.m
===================================================================
--- /issm/trunk/src/m/classes/public/graddetection.m	(revision 2759)
+++ /issm/trunk/src/m/classes/public/graddetection.m	(revision 2759)
@@ -0,0 +1,33 @@
+function [direction,direction2]=graddetection(md)
+%GRADDETECTION detect gradient of control method between steps nsteps+1 and nsteps
+%
+% Usage: direction=graddetection(md);
+
+%keep copy of md: 
+md2=md;
+
+%solve first batch of control methods, with given settings.
+md2=solve(md2,'analysis_type','diagnostic');
+
+%record final optimized parameter. 
+parameter1=md2.results.diagnostic.parameter;
+
+%plug optimized parameter in model. 
+md2.(md2.results.diagnostic.control_type)=parameter1;
+
+%put nsteps to 1: 
+md2.nsteps=1;
+md2.optscal=md2.optscal(end)*ones(md2.nsteps,1);
+md2.fit=md2.fit(end)*ones(md2.nsteps,1);
+md2.cm_jump=md2.cm_jump(end)*ones(md2.nsteps,1);
+md2.maxiter=md2.maxiter(end)*ones(md2.nsteps,1);
+
+%rerun control method with optimized parameter, only for 1 more step.
+md2=solve(md2,'analysis_type','diagnostic');
+
+%get optimized parameter after 1 more step. 
+parameter2=md2.results.diagnostic.parameter;
+
+%return relative  difference between nsteps+1 and nsteps;
+direction=(parameter2-parameter1)./parameter1;
+direction2=(parameter2-parameter1);