clear
  tdata=100:100:1000
  cdata=1e-03*[4.54,4.99,5.35,5.65,5.90,6.10,6.26,6.39,6.50,6.59];
  x0=[0.2,0.05,0.05];
  x=lsqcurvefit('curvefun1',x0,tdata,cdata)
  f=curvefun1(x,tdata)  
  x