Encoundered error during compiling program for solving differential equation ode45 using MATLAB R2013a.

Came across 'The expression to the left of the equals sign is not a valid target for an assignment' during compiling ode45 differential equation solver line 29, what would be the possible error.

Answer 1

[Torsten]

if s==0
     u=b*x(2)+c*x(1)-3*(1+abs(x(2)))*sign(s);
end

Best wishes

Torsten.

Answer 2

[Steven Lord]

I believe line 29 is:

if s=0;

A single equal sign performs assignment. Two equal signs performs comparison.

x = 5; % Assign the value 5 to x
x == 5 % Returns true if x is equal to 5 and false if it is not.

The if keyword wants a comparison, not an assignment, as its condition.