matlab - using options in lsqcurvefit -

matlab - using options in lsqcurvefit -

i set options to

options=optimset('levenbergmarquardt', 'on')

and employ lsqcurvefit below,

[x,resnorm,residual,exitflag,output] = lsqcurvefit(@myfun, [0.01 0.3], xdata, ydata, [-inf -inf], [inf inf], options)

but problem don't why output :

output =

firstorderopt: 3.4390e-07 iterations: 4 funccount: 15 cgiterations: 0 algorithm: 'large-scale: trust-region reflective newton' message: [1x425 char]

does mean matlab did not utilize algorithm levenberg marquardt?

but did set options levenberg marquardt algorithm!!!

i'd appreciate help.

sometimes specific algorithm not suitable specific configuration of optimization problem. in these cases matlab "falls back" default optimization algorithm. might case specific problem/configuration matlab unable utilize levenberg-marquardt algorithm.

read docs see if case.

matlab levenberg-marquardt