Plotting a contour of a function with one input variable

Hi

My function essentially has 2 inputs , x and y, but they're in the form theta = (x;y). So the first line of my code is x = theta(1,1), y = theta(2,1), and my function takes one input theta which should be a 2x1 matrix.

I need to plot a contour of the function with x and y taking certain values. But when I use "fcontour" I get 'not enough input arguments'. I'm not able to change the number of inputs for my function, it has to take a single input theta.

Any help would be appreciated for the contour plot! Thank you

Answer 1

[Chris]

exes = linspace(-2*pi,2*pi);
whys = exes;
theta = [exes',whys'];
takeOneInput(theta)

You can pack as much as you want into an input, depending on the data type. This one uses fcontour.

theta2.fun = @(x,y) sin(x) + cos(y);
theta2.xyinterval = [-2*pi,2*pi, -2*pi, 2*pi]

theta2 = struct with fields:
           fun: @(x,y)sin(x)+cos(y)
    xyinterval: [-6.2832 6.2832 -6.2832 6.2832]

takeAnotherInput(theta2)

function takeOneInput(theta)
    [x,y] = meshgrid(theta(:,1),theta(:,2));
    f = sin(x) + cos(y);
    contour(theta(:,1),theta(:,2),f);    
end

function takeAnotherInput(theta)
    fcontour(theta.fun,theta.xyinterval);
end

But if you are designing the function, why is it only permitted to take one input?