Minimize misfit in MATLAB

Dear everyone I have codes for calculation of misfit for a distribution of model parameters calculated based on true parameters by a function and stored in a matrix. I have calculated the misfit (Likelihood) for the data. I tried to apply the optimization methods on the misfit matrix, but I haven't been successful so far. I was wondering any one can help me? I need to find the i and j values where M(i,j)=0. Thanks in advance. Cheers

    Vp1=3300;
    Vs1=1500;
    rho1=2390;
    Vp2=3850;
    Vs2=2000;
    rho2=2510;

    i1=[pi*5/180 pi*10/180 pi*15/180];   

    Rpp = zoeppritz(Vp1,Vs1,rho1,Vp2,Vs2,rho2,i1);
    zm=Rpp;

    clear rho1
    clear rho2
    rho1 = linspace(2090,2590,101);
    rho2 = linspace(2210,2710,101);

   MS=zeros(101,101);
    for i=1:101
        for j=1:101

    Rpp1 = zoeppritz(Vp1,Vs1,rho1(1,i),Vp2,Vs2,rho2(1,j),i1);
    sigma=.1;

        MS(i,j)=(norm(zm-Rpp1)^2)/(sigma^2);

        end
    end

    S = log10(MS);