function Mesh_T6(evalfun,c2range,c3range,tol)
% Creates a contour map of ||evalfun||^2
% Inputs:
%   evalfun           String that names a function M-file for 
%                       evaluating error coefficients given c2 and c3
%   c2range           Two parameter vectors specifying lowest and highest
%    & c3 range         values of c2 and c3 to be plotted
%   tol               Maximum viewable value of above ratio
%                       Default value is 1
%                       Reduce tol to focus area on minimums

% Default mesh spacing is 1/100 the difference in c2range & c3range
C2spacing = (c2range(2)-c2range(1))/100;
C3spacing = (c3range(2)-c3range(1))/100;

C2 = c2range(1):C2spacing:c2range(2);
C3 = c3range(1):C3spacing:c3range(2);

if nargin < 4
    tol = 1;
end

for i = c2range(1):C2spacing:c2range(2)
    for j = c3range(1):C3spacing:c3range(2)
        t = feval(evalfun,i,j);
        ifix = int16((i-c2range(1))/C2spacing+1); %ifix integer value from 1 to 101
        jfix = int16((j-c3range(1))/C3spacing+1); %jfix integer value from 1 to 101
        Z(jfix,ifix) = sum(t.^2); % sum of squares
        if (Z(jfix,ifix) > tol)
            Z(jfix,ifix) = tol;
        end
    end
end

mesh(C2,C3,Z);
xlabel('c2')
ylabel('c3')
zlabel('sum of squares')

end