Error 'Assignment has more non-singleton rhs dimensions than non-singleton subscripts'

Hi, I'm getting following errors while using mle with a custom pdf:

Assignment has more non-singleton rhs dimensions than non-singleton subscripts

Error in fminsearch (line 200) fv(:,1) = funfcn(x,varargin{:});

Error in mlecustom (line 184) fminsearch(llf,start,opts,uncensData,censData,uncensFreq,censFreq,fun1Args,fun2Args,checkFunVals,lb,ub);

Error in mle (line 237) phat = mlecustom(data,varargin{:});

Error in mleexample (line 58) mle(DT,'pdf',pdf,'start',start);

MY SCRIPT:

    pdf=@(x,a,b)h(x,a,b);
    mi=0.3;
    sigma=0.2;
    start=[mi,sigma];
    mle(DT,'pdf',pdf,'start',start);

    function s=h(x,a,b)
    k=a^2/b;
    phi=b/a;
    i=0;
    s=ones(1,length(x));
       while i<=29
            s=s.*(x.^(k-1).*(exp(1).^(-x./phi))/(gamma(k)*phi^k));
            i=i+1;
       end
    end

Can somebody help? Thank you very much.