matlab - Fortran minimization of a function with additional arguments

Question

In fortran I have an external optimization routine that takes as an input the function f(x) and the starting point and returns the value for local minimum. For example if the function is called minimum:

minimum(f,x0,xopt)

The problem is that the function I need to minimize depends on some additional arguments that are not part of the minimization routine: f(x,data).

How can I overcome this issue. In matlab I would use anonymous function

g=@(x) f(x,data)

minimum(g, x0, xopt)

However as I understant in fortran 90 there are no anonymous function.

Thanks.

Answer 1

You don't need anonymous functions for this. Your Matlab example is also not anonymous in the end, it has a name g.

Fortran internal functions are of great use here (Fortran 2008 feature, but supported in gfortran and ifort, not supported in Solaris Studio):

call minimum(g, x0, xopt)

contains

  real function g(x)
    real, intent(in) :: x
    g = f(x,data)
  end function

end