reverse the output order of the constraint function argument of fmincon

I frequently use fmincon to solve for a bunch of equality constraints, but my problems have no inequality constraints. My equality constraints are typically defined as an anonymous function in the workspace that calls fmincon, e.g.,

f   = @(x,b) a*x + b

It would be so much more convenient if I could simply pass f as an argument to fmincon, e.g.,

soln = fmincon(obj,x,[],[],[],[],[],[],@(x) f(a,b))

but because fmincon expects equality constraints in the second argument, I have to write a separate nested function with two output variables, and all of the data to that extra function. Is there a workaround for this? I can think of two ways it could be done: easiest would be for matlab to provide a field of the fmincon options struct that reversed the output arguments of the constraint function. Alternatively, is there a way to write an anonymous function with two output arguments? Thanks!

Answer 1

[Walter Roberson]

@(x) deal([], f(x, b))