fminbnd supplies anonymous function with a vector rather than a scalar

My M-file function Y = MEP_ObjFun(P,B,R,T) requires inputs scalar P and [1 x N] vectors B, R, T and returns a scalar Y.

When I call this anonymously using fminbnd()

   Popt = fminbnd(@(y)MEP_ObjFun(y,B,R,T),lb,ub);

and inquire size(P) inside of MEP_ObjFun.m it returns [1 x N].

Why is fminbnd assuming I want to pass a vector rather than a scalar and how do I control this?

Thank you, Grey

[Sean de Wolski]

Any chance you overwrite P in MEP_ObjFun?

[Grey Nearing]

P is not overwritten in the function, which is reporduced below.

function Y = MEP_ObjFun(P,B,R,T)

size(P)

G = 11*P*R./((12*B)-P);

Phat = P_from_G(G,T);

Y = (P-Phat)^2;

end

[Grey Nearing]

Problem: ub is a vector.

Solved.

[Laura Proctor]

I just tried the same syntax for FMINBND as above and the value for P was always a scalar. Make sure that you are calling the correct function:

which -all fminbnd

Answer 1

[Grey Nearing]

Problem: One (or both) of the bounds (lb, ub) is a vector.