How to plot an anonymous function with multiple variables

I need to plot a function that I have created as an anonymous function

I appreciate any help I can get!

Thanks!

[Stephen23]

https://web.archive.org/web/20220731043101/https://webcache.googleusercontent.com/search?q=cache%3Aa9uU5UdGKagJ%3Ahttps%3A%2F%2Fwww.mathworks.com%2Fmatlabcentral%2Fanswers%2F1761220-how-to-plot-an-anonymous-function-with-multiple-variables

https://web.archive.org/web/20220731043520/https://www.mathworks.com/matlabcentral/answers/1761220-how-to-plot-an-anonymous-function-with-multiple-variables

Answer 1

[Voss]

With the function as given, you can calculate its value for each a in a loop:

Func2 = @(a,b,c) 20*b^2-4*a^6+20+4*c;

a = 0:0.25:10;
b = -3;
c = 8;

vals = zeros(size(a));
for ii = 1:numel(vals)
    vals(ii) = Func2(a(ii),b,c);
end

and plot:

plot(a,vals,'.-')

Or you could vectorize the function and calculate its values for all a at once:

Func2 = @(a,b,c) 20*b.^2-4*a.^6+20+4*c; % now any of a,b,c can be a vector (or all of them, if they are the same size)

a = 0:0.25:10;
b = -3;
c = 8;

vals = Func2(a,b,c);

and plot:

plot(a,vals,'.-')

[Greg]

Ah, I hadn’t even seen the vals function before. Thank you! What does the “.-“ do in the plot function?

[Voss]

vals is a variable I made to store the values of Func2 at the given a, b, c. The line

vals = Func2(a,b,c);

evaluates the function Func2 at a, b, c, and stores the result in vals.

.- plots the line using dots as a data marker ( . ) and using a solid line ( - )