Can't colour a 3D map?

Please help, I have got the 3D graph, and I want to colour it according to its Z-axis value.

%------------------------------------------------------------------------------------------------------

%Function:

function C = bs ( Interest, Volatility, Stock, StrikePrice, TimeToMaturity )

d1 = (log(Stock ./ StrikePrice) + (Interest + (Volatility .^ 2) ./ 2) .* TimeToMaturity) ./ (Volatility .* sqrt(TimeToMaturity));

d2 = (log(Stock ./ StrikePrice) + (Interest - (Volatility .^ 2) ./ 2) .* TimeToMaturity) ./ (Volatility .* sqrt(TimeToMaturity));

C = normcdf(d1) .* Stock - normcdf(d2) .* StrikePrice .* exp(-Interest .* TimeToMaturity);

end

%------------------------------------------------------------------------------------------------------

%Code:

stock = 0 : 0.01 : 1100;

time = 0/52 : 1/52 : 9/52;

[X, Y] = meshgrid(stock, time);

Z = bs(0.05, 1.13, X, 800, Y);

surf(X, Y, Z)

colormap hsv

colorbar

xlabel('Stock Price')

ylabel('Time')

zlabel('Option Price')

grid on

%------------------------------------------------------------------------------------------------------

Thank you very much!

Answer 1

[Walter Roberson]

By default surf() already colors according to Z axis value.

[Tiancong]

Thank you for your answer. However, after implementing the code, why my 3d plot have no colour?

[Walter Roberson]

Sorry I do not have the Stats toolbox to test the code with.

Does the same problem occur if you leave out the "colormap" command?

Is your surface showing up flat? If it is then your Z might be constant.