sscontrol

 stepsize control. 
 stepok=1 if OK; 0 for return to core loop; -1 to abort cont 
 u1,lam1,... as in and outputs since they may be overwritten in cfail, 
 for instance by mesh-refinement

0001 function [p,stepok,u1,lam1,res,iter,Gu,Glam]=sscontrol(p,u1,lam1,res,iter,Gu,Glam,dss)
0002 % stepsize control.
0003 % stepok=1 if OK; 0 for return to core loop; -1 to abort cont
0004 % u1,lam1,... as in and outputs since they may be overwritten in cfail,
0005 % for instance by mesh-refinement
0006 dlam=lam1-p.lam; stepok=1; ds=p.ds; 
0007 if((res>p.tol || abs(dlam)>p.dlammax) && abs(ds)>p.dsmin) % bad step, reduce step size
0008    p.ds=sign(ds)*max(abs(ds)/2,p.dsmin); 
0009    if(p.vsw>0); fprintf('stepsizecontrol: dlam=%g, res=%g, reducing ds to %g\n',dlam,res,p.ds); end;
0010    stepok=0; return; 
0011 end
0012 if(iter<p.dsinciter && abs(ds)<p.dsmax/p.dsincfac ...
0013         && abs(dlam)<p.dlammax/p.dsincfac) % very good step, increase stepsize
0014    p.ds=ds*p.dsincfac; 
0015    return; 
0016 end;      
0017 if(res>p.tol && abs(ds)<1.1*p.dsmin) % very bad, minimal stepsize but no convergence
0018   [p,stepok,u1,lam1,res,iter,Gu,Glam]=cfail(p,u1,lam1,res,iter,Gu,Glam,dss); 
0019 end
0020   
0021