The function f is plotted over the default domain –2π < x < 2π, –2π < y < 2π. MATLAB® software chooses the computational grid according to the amount of variation that occurs; if the function f is not defined (singular) for points on the grid, then these points are not plotted.
If f is a function of the variables u and v (rather than x and y), then the domain endpoints umin, umax, vmin, and vmax are sorted alphabetically. Thus, ezcontour(u^2 - v^3,[0,1],[3,6]) plots the contour lines for u2 - v3 over 0 < u < 1, 3 < v < 6.
ezcontour automatically adds a title and axis labels.
The following mathematical expression defines a function of two variables, x and y.
ezcontour requires a sym argument that expresses this function using MATLAB syntax to represent exponents, natural logs, etc. This function is represented by the symbolic expression
syms x y f = 3*(1-x)^2*exp(-(x^2)-(y+1)^2)... - 10*(x/5 - x^3 - y^5)*exp(-x^2-y^2)... - 1/3*exp(-(x+1)^2 - y^2);
For convenience, this expression is written on three lines.
Pass the sym f to ezcontour along with a domain ranging from -3 to 3 and specify a computational grid of 49-by-49.
In this particular case, the title is too long to fit at the top of the graph so MATLAB abbreviates the string.