Not enough input arguments error

Hi, I'm very new to MATLAB (and very bad as well) so I'm having a problem here and would be very thankfull if somebody could help me with solving it.

I'm trying to change a program but at some poit I'm getting an error "Not enogh input arguments".

This program should be giving me a surface as a result. And as an input a have some entry conditions, some boundary conditions, and a function (below).

Since the fuctions depends on two argument of which one is not actually used I put it with the power of 0. In this case it gives me "not enogh input arguments" error. In case I errase not used argument I get another error "Conversion to function_handle from double is not possible" which I don't understand at all what it means.

Thanks.

l=1;
ph=3;
u01=@(p) (abs(cos(pi*ph*((p/l)^4)))^3);
c=1;
a = 1;
b = 1;
q = 0.5;
beta1 = 0.3;
beta2 = 0.6;
phi = @(k) k*exp(-q*k);

f01 = @(p,k) exp(-a*k)*p^0;
f02= @(p,k) 0;

N = 40
h = 1/N
T = 5*l/c;
tau = 0.9*h/c
Nt = round(T/tau)
u = zeros(Nt,N);
r = c*tau/h;
x = linspace(0,l,N);
t = linspace(0,T,Nt);


for j= 1:N
    if x(j)<beta1 & x(j)>beta2
        f(1,j)=f02(x(j));
    end
    if x(j)>beta1 & x(j)<beta2
        f(1,j)=f01(x(j));
    end
end
for m = 1:Nt-1
    u(m+1,1) = phi(t(m+1));
    for i = 2:N
        u(m+1,i) = 1/(r+1)*(u(m,i)+r*u(m+1,i-1)+tau*f(x(i) ,t(m)));
    end
end
surf(x,t,u)
shading interp
xlabel('x')
ylabel('t')
zlabel('u')
title('u(x,t)')

[Jan]

You have mentioned two different codes, a partial error message and some code. It s not clear, which of the two versions the posted code is. Please post the real code with a complete copy of the error message, such that the readers do not have to guess, where the problem occurs.

Answer 1

[Jan]

What about replacing:

for j= 1:N
    if x(j)<beta1 & x(j)>beta2
        f(1,j)=f02(x(j));
    end
    if x(j)>beta1 & x(j)<beta2
        f(1,j)=f01(x(j));
    end
end

by

f01      = @(x) exp(-a * x);
f        = zeros(1, N);
index    = (beta1 <= x & x <= beta2);
f(index) = f02(x(index));

By the way, your code ignores the value x(j)==beta1 and x(j)==beta2