function f = R_alpha(FunctionCell)

fnum = size(FunctionCell,1);
alpha = 0;
f = @(x,y,z) FunctionCell{1}(x,y,z) + FunctionCell{2}(x,y,z)...
        + power(power(FunctionCell{1}(x,y,z),2) + power(FunctionCell{2}(x,y,z),2)...
                - 2.* alpha.* FunctionCell{1}(x,y,z).* FunctionCell{2}(x,y,z),1/2);
for i = 3:fnum
        
    f = @(x,y,z) f(x,y,z) + FunctionCell{i}(x,y,z)...
        + power(power(f(x,y,z),2) + power(FunctionCell{i}(x,y,z),2)...
                - 2.* alpha.* f(x,y,z).* FunctionCell{i}(x,y,z),1/2);
        
end
       
f = @(x,y,z) 1./(alpha+1).*f(x,y,z);

end