How should I use erfc?

The equation in the photo is the analytic solution of the ED model(equilibrium-dispersive model).

We want to express the expression of the photo in MATLAB.

Shouldn't variables be used in erfc?

Please tell me how to use erfc

The variables are x and t.

c(x,t)

Please tell me how to put it in matlab.

[Rik]

What did you try so far?

Have a read here and here. It will greatly improve your chances of getting an answer.

Answer 1

[Walter Roberson]

When you use simulink, generally speaking each time you call a function other than the basic mathematical operators, you should assign the result to a variable. The variable should have already been assigned zeros() that is the same size as the result you expect from the function call.

t1 = zeros(1,1);
t2 = zeros(1,1);
t3a = zeros(1,1);
t3b = zeros(1,1);
t4 = zeros(1,1);
t5a = zeros(1,1);
t5b = zeros(1,1);

t1 = sqrt(P_e/2);
t2 = L./u .* (1 + a.*F);
t3a = t2 .* x - t;
t3b = t2 .* x + t;
t4 = sqrt(t2 .* t);
t5a = erfc(t1 .* t3a ./ t4);
t5b = erfc(t1 .* t3b ./ t4);

and so on.

Not all of the above temporary variables are required: some of them exist only to make it easier to write both erfc() sub-expressions