Matlab Introduction Course for Undergrads

Hey, I have following function

x = linspace(-0.5,0.5);
y = linspace(-0.5,0.5);
[X,Y] = meshgrid(x,y);
V = 4*(((exp(-20*(((X-0.25)^2) + (Y-0.25)^2)))) + exp(-20*(((X-0.25)^2 + (Y-0.75)^2))) + exp(-20*(((X-0.75)^2 + (Y-0.5)^2))));
figure
contour(X,Y,V,'ShowText','on')

I want to display the function text so I can debug, because Matlab only outputs arrays with zeros. So something is wrong with how I typed in the function.

i.e

Is this possible in MATLAB 2016b?

Thank you

[Adam]

Simplest option would probably be to split it across a number of lines with intermediate variables. Maths all on one line with so many brackets may look neat and space-saving, but it can be more trouble than it is worth when it doesn't work correctly.

[Stephen23]

@Hakan Ole Ensrud Abediy: Splitting this onto several intermediate calcaultions, exactly as Adam has suggested, will be the simplest answer. Then you can check (by hand) that each intermediate step is correct.

[José-Luis]

Apparently, live script will prettify whatever equation you insert. That could be another way to check.

Especially useful if you are familiar with Latex.

[Rena Berman]

(Answers Dev) Restored edit

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[Walter Roberson]

Your bug is that you used the ^ operator instead of the .^ operator. For a square matrix Z, Z^2 is Z*Z, the matrix algebraically multiplied by itself, whereas you want Z.*Z, which is each element multiplied by itself.

Answer 2

[shegaw mamo]

function dx = cancerhealthcells(~, x)

dx = [2; 1];

L=15;

ommega=50

alpha1 = 0.1;

alpha2 = 0.45;

kappa1 = 0.65;

kappa2 = 1;

beta1 = 0.11;

beta2 = 0.15;

epsilon = 0.05;

gamma = 0.35;

dx(1) = alpha1*x(1)-alpha1*x(1).^2./kappa1-beta1*x(1)*x(2)-epsilon*gamma*x(1);

dx(2) = alpha2*x(2)-alpha2*x(2).^2./kappa2-beta2*x(1)*x(2)-gamma*x(2);

Question: Ommega and L are not in the system of equation. How we can develop matlab syntax including ommega and L using ode45?

[Walter Roberson]

What leads you to expect that they should be present?