When I run fminunc, it works fine; however, when I try and run it
with the hessian I get the following error when I call feval:

??? One or more output arguments not assigned during call to 'feval'.

Error in ==> C:\MATLAB6p5\toolbox\optim\fminunc.m
On line 149 ==> f = feval(funfcn{3},x,varargin{:});

Error in ==>
C:\MATLAB6p5\work\TelOptimization\calcOptParLiveCells.m
On line 8 ==> [x,fval,exitflag,output,grad,hessian] =
fminunc(@calcLiveCellsDev,x0,options,0,0);

What could be causing this error?

In article <eecb63f.-1@webx.raydaftYaTP>,
 Natalie <na104@columbia.edu> writes:
 >When I run fminunc, it works fine; however, when I try and run it
 >with the hessian I get the following error when I call feval:
 >
 >??? One or more output arguments not assigned during call to 'feval'.
 >
 >Error in ==> C:\MATLAB6p5\toolbox\optim\fminunc.m
 >On line 149 ==> f = feval(funfcn{3},x,varargin{:});
 >
 >Error in ==>
 >C:\MATLAB6p5\work\TelOptimization\calcOptParLiveCells.m
 >On line 8 ==> [x,fval,exitflag,output,grad,hessian] =
 >fminunc(@calcLiveCellsDev,x0,options,0,0);
 >
 >What could be causing this error?

obviously the optimizer wants the Hessian evaluated by you! use 
options=optimset('Hessian','off');
or ('LargeScale','off')
hth
peter