Perform Information Ratio Maximization

I have a problem with this function

objFun = @(targetReturn) -infoRatioTargetReturn(targetReturn,pAct); options = optimset('TolX',1.0e-8); [optPortRetn, ~, exitflag] = fminbnd(objFun,0,max(portRetnAct),options);

[optInfoRatio,optWts] = infoRatioTargetReturn(optPortRetn,pAct); optPortRisk = estimatePortRisk(pAct,optWts)

Error messege:

Error in @(targetReturn)-infoRatioTargetReturn(targetReturn,pAct)

Error in fminbnd (line 228) x= xf; fx = funfcn(x,varargin{:});