Plot surface from non-anonymus function

Hello guys,

I'd like to plot a surface from a global function. I don't know how to create the function, so it is applied to every value in a multidimensional array (mesh grid). There plenty of examples using anonymous functions, but I haven't found any from a non-anonymous one (which I call "global").

Take this function as an example

function z = test(w)
    x = w(1);
    y = w(2);
    z = 2*x.^2 + 2*y.^2 +10*(1.1*y.^2 +3*x.^2).^0.5;
end

Is it possible?

Regards,

Santiago

Answer 1

[Star Strider]

See if this does what you want —

function z = test(w)
    x = w{1};
    y = w{2};
    z = 2*x.^2 + 2*y.^2 +10*(1.1*y.^2 +3*x.^2).^0.5;
end

x = -10:10;
y = -15:5;
[W{1},W{2}] = ndgrid(x,y);

Z = test(W);

figure
surf(W{1},W{2},Z)
grid on

Note that I created ‘w’ as cell arrays to pass its elements as matrices. Other than that change, your function is as you wrote it.

[Santiago Ortiz Laverde]

Thank you!, It worked. I just didn't know about 'cell arrays'.

[Star Strider]

As always, my pleasure!

They’re quite useful!

Answer 2

[Hernia Baby]

clc,clear,close all;

w = [1:10;2:11];
x = w(1,:);
y = w(2,:);

f = @(x,y) 2*x.^2 + 2*y.^2 +10*(1.1*y.^2 +3*x.^2).^0.5;

[X,Y] = meshgrid(x,y);
z = f(X,Y);

figure
surf(X,Y,z)
grid on