fsolve problem-I must be missing something

I am trying to fit two vectors A and L using the function:

function F = onesite(x,A,L)
Amax=x(1)
Kd=x(2)
F=A-(Amax*Kd*(L-(A/Amax))/(1+Kd*(L-(A/Amax))))
end

to find the best fit scalars Amax and Kd by defining the start points for x:

x=[1:10]

then using fsolve to find the optimal values

f=fsolve(@onesite,x,A,L)

Despite defining A,L, and the start points for x, I get the error:

Error using onesite (line 4)
Not enough input arguments.

What am i missing here?

Thanks

Answer 1

[Star Strider]

One possible solution:

f=fsolve(@(x)onesite(x,A,L),X0);

where ‘X0’ is your vector of initial estimates for ‘x’.

It’s also a good idea to vectorise your functions (doing element-wise or array operations) unless you specifically want to do matrix operations:

F=A-(Amax.*Kd.*(L-(A./Amax))./(1+Kd.*(L-(A./Amax))));

Putting periods in front of certain operators converts them from matrix to array operators.

[John Hackett]

f=fsolve(@(x)onesite(x,A,L),X0);

Solves the problem. Thank you very much!

[Star Strider]

My pleasure!