Error on contour plot stability region Runngekutta

Hello I am trying to plot a region of stability of the Runge Kutta 4th order here is the following code in a script

[X,Y] = meshgrid(-5:0.01:5,-5:0.01:5);
  Mu = X+i*Y;
  R = 1 + Mu + .5*Mu.^2 + (1/6)*Mu.^3 + (1/24)*Mu.^4;
  Rhat = abs(R);
  contourplot(X,Y,Rhat,[1]);

I get the error that contourplot is an undefined function. the contour plot should look like this :

Any help would be appreciated

Answer 1

[Walter Roberson]

contourplot() is not a function defined by Mathworks, and it does not appear to be defined by any File Exchange contributions either.

The contour() routine provided by MATLAB would only draw outlines. The contourf() routine would fill those outlines, but with constant colors, not with a shaded surface like that.

[Janvier Solaris]

Thank you for your answer Walter; Is there any way to get it to look just like the outline of the shape? I have tried contourf and it does just what you said but with no discernable shape

[Walter Roberson]

I would suggest

surf(X, Y, Rhat, 'edgecolor', 'none');
colormap(gray(256))
lighting gouraud